OFFSET
1,1
LINKS
Anthony Sand, Table of n, a(n) for n = 1..22
FORMULA
For a number n with d1 digits there are d1Pd2 = d1!/(d1-d2)! substrings generated by sampling and permutating d2 digits from the original number. When n=132 and d2=2, these substrings are 13, 31, 32, 23, 12, 21. When n=112 and d2=2, the substrings are 11, 11, 12, 21, 12, 21. Sum(x,d) is defined as the sum of d-digit substrings for a number x. The sequence above is those numbers such that sum(x,d) = x, where d = 2, 2, 2, 3, 4, 5, 5, 6, 7, 7, 8, 9, 10, 11, 11, 11, 12, 12, 13, 13, 14, 14.
EXAMPLE
sum(132,2) = 13 + 31 + 32 + 23 + 12 + 21 = 132.
CROSSREFS
KEYWORD
base,nonn
AUTHOR
Anthony Sand, Apr 28 2014
STATUS
approved