A144931 a(n) is the Mersenne number exponent for A144932(n).

1, 7, 11, 15, 17, 19, 21, 23, 27, 29, 39, 41, 47, 49, 55, 57, 73, 75, 83, 93, 95, 101, 103, 107, 109, 113, 115, 117, 119, 123, 125, 127, 131, 137, 139, 143, 155, 161, 163, 165, 169, 171, 177, 183, 185, 191, 199, 203, 207, 211, 213, 217, 221, 225, 237, 241, 243, 255, 257, 259

Offset

1,2

Links

Table of n, a(n) for n=1..60.

Prog

(PARI) forstep(m=1, 10^6, 2, n=sqrtint(2^m-1); if(2^m-1-n^2<n, print1(m, ", ")))

Crossrefs

Cf. A000225, A017910, A144932.

Sequence in context: A120687 A194468 A053217 * A166257 A192992 A335652

Adjacent sequences: A144928 A144929 A144930 * A144932 A144933 A144934

Keyword

nonn

Author

Reikku Kulon, Sep 25 2008

Extensions

Edited and extended by Max Alekseyev, Oct 12 2009

Status

approved