We recognize how important archival material is for supporting advancements in mathematics research. That is why we have opened access to all available archived articles, back to Volume 1, Issue 1 (or the first issue available) of each of the primary mathematics journals from 4 years after publication to the 1st issue, which means back to early 1960s for several titles.
200,000 articles are now freely available to the mathematics community via ScienceDirect, for the following titles:
Title
 Year range
 Total nr of Articles freely available^{i} 
Advances in Applied Mathematics

19802011

>

1,395 
Advances in Mathematics

19652011

>

4,852 
Annales de l'Institut Henri Poincaré (C)

19972011

>

828 
Annals of Mathematical Logic^{ii} 
19701982

>

230

Annals of Pure and Applied Logic^{iii} 
19832011

>

2,107 
Applied and Computational Harmonic Analysis

19932011

>

720 
Applied Mathematical Modelling

19762011

>

4,737 
Applied Mathematics Letters

19882011

>

4,825 
Bulletin des sciences mathématiques

19982011

>

711 
Computational Geometry

19912011

>

1,019 
Computers & Mathematics with Applications

19752011

>

10,402 
Differential Geometry and its Applications

19912011

>

1,036 
Discrete Applied Mathematics

19792011

>

5,928 
Discrete Mathematics

19712011

>

12,975 
Discrete Optimization

20042011

>

292 
European Journal of Combinatorics

19922011

>

2,214 
Expositiones Mathematicae

20012011

>

275 
Finite Fields and Their Applications

19952011

>

734 
General Topology and its Applications^{iv} 
19711979

>

280

Historia Mathematica

19742011

>

2,544 
Indagationes Mathematicae^{v} 
19902011

>

835 
Indagationes Mathematicae (Proceedings)^{vi} 
19691989

>

1,000

Information and Control^{vii} 
19571986

>

1,900

Information and Computation^{viii} 
19872011

>

2,178 
International Journal of Approximate Reasoning

19872011

>

1,518 
Journal de mathématiques pures et appliquées

19972008

>

700

Journal of Algebra

19642011

>

13,810 
Journal of Applied Logic

20032011

>

270 
Journal of Approximation Theory

19682011

>

4,637 
Journal of Combinatorial Theory^{ix} 
19661970

>

430

Journal of Combinatorial Theory, Series A^{x} 
19712011

>

3,910 
Journal of Combinatorial Theory, Series B^{xi} 
19712011

>

2,788 
Journal of Complexity

19852011

>

1,058 
Journal of Computational and Applied Mathematics

19752011

>

9,789 
Journal of Computer and System Sciences

19672011

>

2,581 
Journal of Differential Equations

19652011

>

6,972 
Journal of Discrete Algorithms

20032011 
>

412 
Journal of Functional Analysis

19672011

>

6,420 
The Journal of Logic Programming^{xii} 
19842008

>

350

The Journal of Logic and Algebraic Programming^{xiii} 
20012011

>

373 
Journal of Mathematical Analysis and Applications

19602011 
>

21,431 
Journal of Multivariate Analysis

19712011

>

3,317 
Journal of Number Theory

19692011

>

4,309 
Journal of Pure and Applied Algebra

19712011

>

5,775 
Journal of Symbolic Computation

19852011

>

2,011 
Linear Algebra and its Applications

19682011

>

11,057 
Mathematical and Computer Modelling^{xiv} 
19882011

>

6,392 
Mathematical Modelling^{xv} 
19801987

>

600

Science of Computer Programming

19812011

>

1,464 
Stochastic Processes and their Applications

19732011

>

3,731 
Theoretical Computer Science

19752011

>

10,187 
Topology^{xvi} 
19622011

>

1,922 
Topology and its Applications^{xvii} 
19802011

>

5,449 
^{ i}Total number of articles calculated from 4 years after publication (August 2016 at the time of this calculation) back to Volume 1, issue 1 or the 1st issue available. The numbers exclude editorial board listings, author indexes etc.
^{ii} Continued as Annals of Pure and Applied Logic
^{iii} Formerly known as Annals of Mathematical Logic
^{iv} Continued as Topology and its Applications
^{v} Incorporating Indagationes Mathematicae (Proceedings)
^{vi} Incorporated into Indagationes Mathematicae
^{vii} Continued as Information and Computation
^{viii} Formerly known as Information and Control
^{ix} Continued as Journal of Combinatorial Theory, Series A and Journal of Combinatorial Theory, Series B
^{x} Formerly part of Journal of Combinatorial Theory
^{xi} Formerly part of Journal of Combinatorial Theory
^{xii} Continued as The Journal of Logic and Algebraic Programming
^{xiii} Formerly known as The Journal of Logic programming
^{xiv} Formerly known as Mathematical Modelling
^{xv} Continued as Mathematical and Computer Modelling
^{xvi} Title discontinued as of 2012
^{xvii} Formerly known as General Topology and its Applications