A079465 Numbers n such that the "inventory" A063850 of n is a perfect square.

6, 55, 116, 161, 255, 511, 666, 969, 996, 5311, 9666, 9999, 12255, 12525, 12552, 41199, 41919, 41991, 54246, 54264, 54426, 71177, 71717, 71771, 72255, 72525, 72552, 77117, 77171, 77711, 78055, 83399, 83939, 83993, 89999, 97117, 97171

Offset

1,1

Links

Table of n, a(n) for n=1..37.

The Inventory Sequences and Self-Inventoried Numbers in www.primepuzzles.net (see Question 7)

Example

The "inventory" of 511 is 1521 (one "5", two "1"s) = 39^2. Hence 1521 belongs to the sequence.

Mathematica

g[n_] := Module[{seen, r, d, l, i, t}, seen = {}; r = {}; d = IntegerDigits[n]; l = Length[d]; For[i = 1, i <= l, i++, t = d[[i]]; If[ ! MemberQ[seen, t], r = Join[r, IntegerDigits[Count[d, t]]]; r = Join[r, {t}]; seen = Append[seen, t]]]; FromDigits[r]]; Select[Range[10^5], IntegerQ[Sqrt[g[ # ]]] &]

Crossrefs

Cf. A063850.

Sequence in context: A085066 A085067 A069508 * A061792 A066514 A281075

Adjacent sequences: A079462 A079463 A079464 * A079466 A079467 A079468

Keyword

base,nonn

Author

Joseph L. Pe, Jan 14 2003

Status

approved