A076159 Numbers k such that k = sod_4 - sod_3 + sod_2 - sod_1, where sod_j is the sum of j-th powers of digits of k.

0, 214, 224, 2374, 4048

Offset

1,2

Links

Table of n, a(n) for n=1..5.

Formula

Sod_4 - sod_3 + sod_2 - sod_1 = sum(d(d-1)(d^2+1)), d's are digits of n.

Example

214 = 2*(2-1)*(2^2+1) + 1*(1-1)*(1^2+1) + 4*(4-1)*(4^2+1);
224 = 2*(2-1)*(2^2+1) + 2*(2-1)*(2^2+1) + 4*(4-1)*(4^2+1).

Mathematica

okQ[n_] := Module[{idn=IntegerDigits[n]}, n==Total[idn^4]-Total[idn^3]+Total[idn^2]-Total[idn]]; Select[Range[0, 5000], okQ]  (* Harvey P. Dale, Jan 14 2011 *)

Crossrefs

Sequence in context: A242793 A335721 A242804 * A258961 A204486 A221807

Adjacent sequences: A076156 A076157 A076158 * A076160 A076161 A076162

Keyword

fini,nonn,full,base

Author

Zak Seidov, Nov 01 2002

Status

approved