A280967 Vampire numbers (definition 1) in binary: n has a nontrivial factorization using n's bits.

159, 175, 287, 303, 315, 318, 319, 343, 350, 351, 375, 567, 574, 575, 591, 603, 606, 623, 627, 630, 636, 638, 679, 686, 687, 699, 700, 702, 735, 750, 763, 765, 1127, 1134, 1135, 1148, 1150, 1167, 1179, 1182, 1183, 1203, 1206, 1212, 1215, 1239, 1243, 1246, 1247, 1251, 1254, 1260, 1271, 1272

Offset: 1

Author

Ely Golden, Jan 11 2017

Keywords

• nonn
• base

Comments

Nontrivial means that there must be at least two factors.

Examples

			175 is a member as 175 = 7 * 25 = 10101111_2 = 111_2 * 11001_2
5887 is a member as 5887 = 7 * 29 * 29 = 1011011111111_2 = 111_2 * 11101_2 * 11101_2
		

Links

• Ely Golden, Table of n, a(n) for n = 1..10000
• Ely Golden, General program for generating vampire number sequences

Crossrefs

Cf. A020342