A075761 Numbers n such that there are at least 3 integers k from the set {2,3,4,5,6,7,8,9} such that the digital sum of each base k representation of n equals k.

13, 17, 19, 21, 25, 29, 31, 33, 37, 41, 57, 61, 65, 73, 85, 91, 121, 129, 133, 145, 169, 225, 253, 257, 261, 265, 281, 301, 325, 337, 361, 385, 505, 513, 757, 785, 841, 1057, 1081, 1093, 1381, 1625, 2080, 2241, 3241, 4117, 4377, 4401, 5125, 8281, 16416

Offset: 1

Author

Paul Lusch, Oct 08 2002

Keywords

• base
• nonn

Comments

13, 33, 37 and 57 work for 4 bases. 85 is the only integer found that works for 5 bases: 3, 4, 5, 7 and 8.

Examples

			91 in base 3 = 10101 and 1 + 0 + 1 + 0 + 1 = 3, which is the base. 91 in base 6 = 231 and 2 + 3 + 1 = 6, which is the base. 91 in base 7 = 160 and 1 + 6 + 0 = 7, which is the base.