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A218161 Recurring digital invariants of order 3. 3
55, 136, 160, 919 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

Table of n, a(n) for n=1..4.

Eric Weisstein's World of Mathematics, Recurring Digital Invariant

EXAMPLE

136: 1^3 + 3^3 + 6^3 = 244

244: 2^3 + 4^3 + 4^3 = 136,

so 136 is an order 3 recurring digital invariant.

MATHEMATICA

lst = {}; f[n_] := Total[IntegerDigits[n]^3]; Do[a = n; Do[a = f[a]; If[a < n, Break[]]; If[a == n && ! n == f[n], AppendTo[lst, n]; Break[]], {3}], {n, 10^3}]; lst

CROSSREFS

Cf. A218246-A218248.

Sequence in context: A063324 A046156 A224459 * A044306 A044687 A250578

Adjacent sequences:  A218158 A218159 A218160 * A218162 A218163 A218164

KEYWORD

base,fini,full,nonn

AUTHOR

Arkadiusz Wesolowski, Oct 22 2012

STATUS

approved

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Last modified June 25 05:58 EDT 2021. Contains 345452 sequences. (Running on oeis4.)