A258159 Numbers n such that A053645(n) (n with the most significant binary digit removed) divides A004526(n) (n with the least significant binary digit removed).

3, 5, 7, 9, 15, 17, 19, 21, 31, 33, 63, 65, 67, 71, 73, 85, 127, 129, 255, 257, 259, 261, 271, 273, 307, 341, 511, 513, 519, 585, 1023, 1025, 1027, 1035, 1055, 1057, 1117, 1365, 2047, 2049, 2071, 2137, 4095, 4097, 4099, 4101, 4103, 4105, 4109, 4111, 4117, 4131, 4135, 4141, 4159

Offset: 1

Author

Ivan Neretin, Jul 26 2015

Keywords

• nonn
• base

Comments

Also, numbers of the form 2^k + d, where d is any divisor of (2^k - 1).

Links

• Ivan Neretin, Table of n, a(n) for n = 1..1091

Programs

Mathematica

Flatten[Table[2^n + Divisors[2^n - 1], {n, 15}]]