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

1, 3, 7, 15, 31, 63, 127, 511, 1023, 4095, 8191, 131071, 524287, 2097151, 4194303, 8388607, 33554431, 67108863, 8589934591, 68719476735, 1099511627775, 4398046511103

Offset

1,2

Comments

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

a(23) >= 562949953421311 = 2^49 - 1, if it exists. - Robert Cunningham, May 26 2026

Links

Table of n, a(n) for n=1..22.

Example

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

Crossrefs

Cf. A000959, A000225.

Sequence in context: A117060 A178460 A351755 * A325920 A351754 A174743

Adjacent sequences: A057610 A057611 A057612 * A057614 A057615 A057616

Keyword

nonn,more

Author

Naohiro Nomoto, Oct 09 2000

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

a(20)-a(22) from Robert Cunningham, May 26 2026

Status

approved