A072896 5th-order digital invariants: the sum of the 5th powers of the digits of n equals some number k and the sum of the 5th powers of the digits of k equals n.

1, 4150, 4151, 54748, 58618, 76438, 89883, 92727, 93084, 157596, 194979

Offset

1,2

References

David Wells, The Penguin Dictionary of Curious and Interesting Numbers, Revised Edition, London, England, 1997, pp. 157, 168.

Links

Table of n, a(n) for n=1..11.

Example

58618 is included because 5^5 + 8^5 + 6^5 + 1^5 + 8^5 = 76438 and 7^5 + 6^5 + 4^5 + 3^5 + 8^5 = 58618.

Mathematica

f[n_] := Apply[Plus, IntegerDigits[Apply[Plus, IntegerDigits[n]^5]]^5]; Select[ Range[10^7], f[ # ] == # &]
di5Q[n_]:=Module[{k=Total[IntegerDigits[n]^5]}, Total[ IntegerDigits[k]^5] == n]; Select[Range[200000], di5Q] (* Harvey P. Dale, Nov 26 2014 *)

Crossrefs

Cf. A072409.

Sequence in context: A106537 A256080 A287514 * A052464 A161752 A145205

Adjacent sequences: A072893 A072894 A072895 * A072897 A072898 A072899

Keyword

nonn,fini,full,base

Author

Robert G. Wilson v, Aug 09 2002

Status

approved