A151942 Table of Self / Colombian numbers and their descendents.

1, 2, 3, 4, 6, 5, 8, 12, 10, 7, 16, 15, 11, 14, 9, 23, 21, 13, 19, 18, 20, 28, 24, 17, 29, 27, 22, 31, 38, 30, 25, 40, 36, 26, 35, 42, 49, 33, 32, 44, 45, 34, 43, 48, 53, 62, 39, 37, 52, 54, 41, 50, 60, 61, 64, 70, 51, 47, 59, 63, 46, 55, 66, 68, 74, 75, 77, 57, 58, 73, 72, 56

Offset: 1

Author

Carl R. White, Jul 13 2009

Keywords

• base
• easy
• nonn
• tabl

Comments

Initially resembles a permutation of the integers, but this is not the case. 101 is the first number to appear twice, descending from both 91 and 100: 91 + 9+1 = 100 + 1+0+0 = 101

Links

• D. R. Kaprekar, The Mathematics of the New Self Numbers [annotated and scanned]
• Index entries for Colombian or self numbers and related sequences

Crossrefs

First column of table is the Self numbers: A003052; First through eighth rows are A004207, A016052, A007618, A006507, A016096, A036227, A036228 respectively.

Formula

T(r,0) are those numbers not of form n + sum of digits of n (Self numbers)

T(r,c) = T(r,c-1) + sum of digits of T(r,c-1)