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.

A298613 Primes formed by the concatenation of 2^k-1 and 2^(k-1)-1.

Table of values

n a(n)
1 31
2 73
3 157
4 12763
5 255127
6 40952047
7 524287262143
8 41943032097151
9 6871947673534359738367
10 7036874417766335184372088831
11 22517998136852471125899906842623
12 14757395258967641292773786976294838206463
13 604462909807314587353087302231454903657293676543

List of values

[31, 73, 157, 12763, 255127, 40952047, 524287262143, 41943032097151, 6871947673534359738367, 7036874417766335184372088831, 22517998136852471125899906842623, 14757395258967641292773786976294838206463, 604462909807314587353087302231454903657293676543]

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

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