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A049303
Numbers k such that k is a substring of 5^k.
2
2, 5, 6, 7, 9, 19, 25, 32, 34, 36, 41, 54, 55, 56, 59, 62, 64, 67, 69, 70, 71, 75, 80, 81, 82, 84, 86, 87, 89, 92, 93, 95, 96, 111, 115, 125, 128, 140, 163, 166, 177, 178, 189, 192, 205, 212, 219, 221, 226, 233, 236, 242, 258, 259, 267, 294, 303, 309, 323, 327, 329
OFFSET
1,1
MATHEMATICA
ss5nQ[n_]:=Module[{len=IntegerLength[n]}, MemberQ[Partition[ IntegerDigits[ 5^n], len, 1], IntegerDigits[n]]]; Select[Range[400], ss5nQ] (* Harvey P. Dale, Jan 06 2013 *)
CROSSREFS
KEYWORD
nonn,base,easy
STATUS
approved