A200768 Sum of the n-th powers of the distinct prime divisors of n.
0, 4, 27, 16, 3125, 793, 823543, 256, 19683, 9766649, 285311670611, 535537, 302875106592253, 678223089233, 30531927032, 65536, 827240261886336764177, 387682633, 1978419655660313589123979, 95367432689201, 558545874543637210, 81402749386839765307625
Offset: 1
Keywords
Examples
a(6) = 793 because the distinct prime divisors of 6 are 2 and 3, and 2^6 + 3^6 = 793.
Links
- Robert Israel, Table of n, a(n) for n = 1..388
Programs
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Maple
f:= proc(n) local p; add(p^n, p = numtheory:-factorset(n)) end proc: map(f, [$1..30]); # Robert Israel, Feb 20 2024
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Mathematica
Prepend[Array[Plus@@First[Transpose[FactorInteger[#]^#]]&,100,2],0] Join[{0},Table[Total[FactorInteger[n][[All,1]]^n],{n,2,25}]] (* Harvey P. Dale, Jan 23 2021 *)
Formula
a(n) = Sum_{p|n} p^n. - Wesley Ivan Hurt, Jun 14 2021