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A139236
Second differences of even superperfect numbers A061652.
11
10, 36, 3984, 57408, 135168, 1073283072, 1152921502459625472, 309485007515502060584828928, 81129019444588191927156162428928, 85070429471267271662301605348656545792
OFFSET
1,1
COMMENTS
Second differences of Mersenne primes A000668, divided by 2 (see A139232).
Also, second differences of superperfect numbers A019279, if there are no odd superperfect numbers.
LINKS
FORMULA
a(n) = A139234(n+1) - A139234(n).
MATHEMATICA
Differences[2^(Select[Range[512], PrimeQ[2^#-1]&]-1), 2] (* Harvey P. Dale, Oct 15 2017 *)
KEYWORD
nonn
AUTHOR
Omar E. Pol, Apr 18 2008
EXTENSIONS
a(6) corrected and more terms from Joerg Arndt, Jul 09 2017
STATUS
approved