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%I #6 Oct 29 2012 13:51:28
%S 80441,86874,253074,376762,922428,982108,1152428,2191663,2755907,
%T 2767918,8139850
%N Recurring digital invariants of order 7.
%H Eric Weisstein's World of Mathematics, <a href="http://mathworld.wolfram.com/RecurringDigitalInvariant.html">Recurring Digital Invariant</a>
%e 2755907: 2^7 + 7^7 + 5^7 + 5^7 + 9^7 + 0^7 + 7^7 = 6586433
%e 6586433: 6^7 + 5^7 + 8^7 + 6^7 + 4^7 + 3^7 + 3^7 = 2755907,
%e so 2755907 is an order 7 recurring digital invariant.
%t lst = {}; f[n_] := Total[IntegerDigits[n]^7]; Do[a = n; Do[a = f[a]; If[a < n, Break[]]; If[a == n && ! n == f[n], AppendTo[lst, n]; Break[]], {92}], {n, 10^7}]; lst
%Y Cf. A218161, A218246-A218247.
%K base,fini,full,nonn
%O 1,1
%A _Arkadiusz Wesolowski_, Oct 24 2012
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