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
Examples
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.
References
- David Wells, The Penguin Dictionary of Curious and Interesting Numbers, Revised Edition, London, England, 1997, pp. 157, 168.
Crossrefs
Cf. A072409.
Programs
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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 *)