A038178 -id:A038178 - cp's OEIS frontend

A135480 Generator for the finite sequence A038178.

0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 81, 512, 2401, 5748, 10553, 16816, 24537, 33716, 44353, 56448, 139982, 170003, 202940, 238793, 277562, 319247, 363848, 411365, 461798, 515147, 857103

Offset: 0

Rolf Pleisch, Feb 06 2008

nonn

G. C. Greubel, Table of n, a(n) for n = 0..1000

Cf. A038178.

Table[1/10*(n - (Mod[n, 10]))*(729*n^2 - 14879*n + 75971) + (Mod[n, 10]), {n, 0, 25}] (* G. C. Greubel, Oct 14 2016 *)

a(n) = 1/10*(n-(n mod 10))*(729*n^2-14879*n+75971)+ (n mod 10).

A246605 Numbers n such that n = (digital root of n)^(number of digits of n).

Original entry on oeis.org

0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 81, 512, 729, 2401, 6561, 32768, 59049, 531441, 2097152, 4782969, 43046721, 134217728, 387420489, 3486784401, 31381059609, 282429536481, 2541865828329, 22876792454961, 205891132094649, 1853020188851841, 16677181699666569, 150094635296999121, 1350851717672992089, 12157665459056928801, 109418989131512359209

Offset: 0

Ivan N. Ianakiev, Aug 31 2014

This is a supersequence of A038178. Its finiteness stems from the fact that the number of digits of (digital root(x))^y is less than y, for every y > 21.

			a(10) = 81 = 9^2 = A010888(81)^A055642(81).

Ivan N. Ianakiev, Table of n, a(n) for n = 0..34

Cf. A010888, A055642, A038178.

lst={0,1,2,3,4,5,6};Do[If[7^n==Mod[7^n,9]^n,AppendTo[lst,7^n]],{n,1,9}];Do[If[8^n==Mod[8^n,9]^n,AppendTo[lst,8^n]],{n,1,9}];Union[Join[lst,Table[9^x,{x,1,21}]]]

cp's OEIS Frontend

A135480 Generator for the finite sequence A038178.

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