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%I #10 Jan 15 2021 02:18:12
%S 0,0,3,7,8,31,10,127,25,80,45,112,28,8191,173,189,282,131071,102,
%T 524287,91,471,798,178528,286,2433,10925,262737,320,3425,534,
%U 2147483647,65819,599598,174765,123150,266,616318400,699053,129646,61789,164524720,5936
%N Sum of the distinct prime factors of 2^n-1.
%H Robert Israel, <a href="/A152057/b152057.txt">Table of n, a(n) for n = 0..500</a>
%F a(n) = A008472(A000225(n)). - _Robert Israel_, Jan 14 2021
%p sopf:= n -> convert(numtheory:-factorset(n),`+`):
%p seq(sopf(2^n-1),n=0..100); # _Robert Israel_, Jan 14 2021
%t Table[Sum[FactorInteger[2^n - 1][[m]][[1]], {m, 1, Length[FactorInteger[2^n - 1]]}], {n, 0, 50}]
%Y Cf. A000225, A008472, A046800, A075708.
%Y Row sums of A060443.
%K nonn
%O 0,3
%A _Roger L. Bagula_, Nov 22 2008
%E Edited by _N. J. A. Sloane_, Nov 26 2008
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