A343888 Smallest positive integer such that the decimal representations of a(n) and of a(n)+9n (both without leading zeros) are permutations of each other.
12, 13, 14, 15, 16, 17, 18, 19, 109, 120, 102, 102, 124, 125, 126, 127, 128, 129, 130, 130, 123, 103, 103, 135, 136, 137, 138, 139, 140, 140, 134, 124, 104, 104, 146, 147, 148, 149, 150, 150, 145, 135, 125, 105, 105, 157, 158, 159, 160, 160, 156, 146, 136, 126, 106, 106, 168, 169, 170, 170
Offset: 1
Examples
102 + 9*11 = 201 which is a permutation of digits of 102, and no smaller number has this feature, hence a(11)=102.
Links
- Rémy Sigrist, Table of n, a(n) for n = 1..8999
Programs
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PARI
a(n) = { for (v=1, oo, if (vecsort(digits(v))==vecsort(digits(v+9*n)), return (v))) } \\ Rémy Sigrist, May 03 2021
Comments