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.

A173427 Decimal value a(n) of the binary number b(n) obtained by starting from 1, sequentially concatenating all binary numbers up to n and then sequentially concatenating all binary numbers from n-1 down to 1.

Table of values

n a(n)
1 1
2 13
3 221
4 7069
5 451997
6 28931485
7 1851651485
8 237010810269
9 60674754606493
10 15532737233548701
11 3976380732916495773
12 1017953467644930815389
13 260596087717395474544029
14 66712598455657932715586973
15 17078425204648505835166758301
16 8744153704780027821877938484637

List of values

[1, 13, 221, 7069, 451997, 28931485, 1851651485, 237010810269, 60674754606493, 15532737233548701, 3976380732916495773, 1017953467644930815389, 260596087717395474544029, 66712598455657932715586973, 17078425204648505835166758301, 8744153704780027821877938484637]

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

Content is available under The OEIS End-User License Agreement.