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%I #16 Mar 05 2020 03:44:38
%S 10,36,3984,57408,135168,1073283072,1152921502459625472,
%T 309485007515502060584828928,81129019444588191927156162428928,
%U 85070429471267271662301605348656545792
%N Second differences of even superperfect numbers A061652.
%C Second differences of Mersenne primes A000668, divided by 2 (see A139232).
%C Also, second differences of superperfect numbers A019279, if there are no odd superperfect numbers.
%H Jinyuan Wang, <a href="/A139236/b139236.txt">Table of n, a(n) for n = 1..16</a>
%F a(n) = A139234(n+1) - A139234(n).
%t Differences[2^(Select[Range[512],PrimeQ[2^#-1]&]-1),2] (* _Harvey P. Dale_, Oct 15 2017 *)
%Y Cf. A000668, A019279, A061652, A139228, A139229, A139230, A139231, A139232, A139233, A139234, A139235, A139237.
%K nonn
%O 1,1
%A _Omar E. Pol_, Apr 18 2008
%E a(6) corrected and more terms from _Joerg Arndt_, Jul 09 2017
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