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A072408 Least number > 1 which equals n-th power of the sum of its digits in decimal base. 2
2, 81, 512, 2401, 17210368, 34012224, 612220032, 20047612231936, 3904305912313344, 13744803133596058624, 8007313507497959524352, 2518170116818978404827136, 81920000000000000 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

Michael De Vlieger, Table of n, a(n) for n = 1..274

FORMULA

a(n) = Min{ x; x=SumDigit[x]^n}=Min{x; x=A007953(x)^n}

a(n) = A046017(n)^n. - Michael De Vlieger, Nov 05 2020

EXAMPLE

n=1: a(1)=2>1; n=9: a(9)=3904305912313344=54^9=(3+9+0+4+3+0+5+9+1+2+3+1+3+3+4+4)^9.

MATHEMATICA

Array[Block[{k = 2}, While[k^# != Total[IntegerDigits[k^#]]^#, k++]; k^#] &, 13] (* Michael De Vlieger, Nov 05 2020 *)

CROSSREFS

Cf. A007953, A046017, A072081-A072083.

Sequence in context: A051391 A041799 A187858 * A318587 A302722 A123177

Adjacent sequences:  A072405 A072406 A072407 * A072409 A072410 A072411

KEYWORD

base,nonn

AUTHOR

Labos Elemer, Jun 17 2002

STATUS

approved

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Last modified May 9 13:42 EDT 2021. Contains 343742 sequences. (Running on oeis4.)