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A181683 Numbers n such that the sum of the square of digits of n^n is a prime. 0
3, 6, 7, 11, 20, 29, 30, 38, 56, 63, 89, 114, 124, 131, 139, 140, 176, 184, 192, 195, 198, 208, 214, 215, 223, 243, 300, 301, 331, 337, 345, 359, 372, 377, 388, 393, 407, 411, 451, 455, 459, 461, 476, 482, 483, 487, 506, 508, 516, 523, 536 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

Table of n, a(n) for n=1..51.

EXAMPLE

6 is in the sequence because 6^6 = 46656 and 4^2 + 6^2 + 6^2 + 5^2 + 6^2 =

  149 is a prime.

MAPLE

with(numtheory):for n from 1 to 540 do: l:=length(n^n) : n0:=n^n: s:=0:for

  m from 1 to l do: q:=n0:u:=irem(q, 10):v:=iquo(q, 10): n0:=v :s:=s+u^2: od:if

  type(s, prime)=true then printf(`%d, `, n):else fi:od:

CROSSREFS

Sequence in context: A258233 A015819 A298794 * A084125 A053478 A269363

Adjacent sequences:  A181680 A181681 A181682 * A181684 A181685 A181686

KEYWORD

nonn,base

AUTHOR

Michel Lagneau, Nov 17 2010

STATUS

approved

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Last modified September 19 06:16 EDT 2020. Contains 337177 sequences. (Running on oeis4.)