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.

A057613 Numbers that are both lucky numbers (A000959) and of form 2^k-1 (A000225).

Original entry on oeis.org

1, 3, 7, 15, 31, 63, 127, 511, 1023, 4095, 8191, 131071, 524287, 2097151, 4194303, 8388607, 33554431, 67108863, 8589934591
Offset: 1

Views

Author

Naohiro Nomoto, Oct 09 2000

Keywords

Comments

a(20) >= 17179869183 = 2^34 - 1, if it exists. - Kevin P. Thompson, Nov 24 2021

Examples

			a(7) = 127 since A000959(27) = A000225(7) = 127 and it is the 7th such number with this property.

Crossrefs

Cf. A000959, A000225.

Extensions

More terms from Mark Weston (mweston(AT)uvic.ca), Oct 16 2001
a(18) from Giovanni Resta, May 10 2020
a(19) from Kevin P. Thompson, Nov 24 2021

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

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