A218248 Recurring digital invariants of order 7.

80441, 86874, 253074, 376762, 922428, 982108, 1152428, 2191663, 2755907, 2767918, 8139850

Offset

1,1

Links

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

Eric Weisstein's World of Mathematics, Recurring Digital Invariant

Example

2755907: 2^7 + 7^7 + 5^7 + 5^7 + 9^7 + 0^7 + 7^7 = 6586433
6586433: 6^7 + 5^7 + 8^7 + 6^7 + 4^7 + 3^7 + 3^7 = 2755907,
so 2755907 is an order 7 recurring digital invariant.

Mathematica

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

Crossrefs

Cf. A218161, A218246-A218247.

Sequence in context: A250080 A251377 A204051 * A102457 A102459 A347906

Adjacent sequences: A218245 A218246 A218247 * A218249 A218250 A218251

Keyword

base,fini,full,nonn

Author

Arkadiusz Wesolowski, Oct 24 2012

Status

approved