cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

A139256 Twice even perfect numbers. Also a(n) = M(n)*(M(n)+1), where M(n) is the n-th Mersenne prime A000668(n).

Table of values

n a(n)
1 12
2 56
3 992
4 16256
5 67100672
6 17179738112
7 274877382656
8 4611686016279904256
9 5316911983139663489309385231907684352
10 383123885216472214589586756168607276261994643096338432

List of values

[12, 56, 992, 16256, 67100672, 17179738112, 274877382656, 4611686016279904256, 5316911983139663489309385231907684352, 383123885216472214589586756168607276261994643096338432]

Started in 1964 by Neil J. A. Sloane | Maintained by The OEIS Foundation Inc.

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