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A139229 First differences of perfect numbers A000396, divided by 2. 10
11, 234, 3816, 16771104, 4278159360, 64424411136, 1152921435350630400, 1329227995784915871174424803906945024, 95780971304118052318168693257235946738152352797163520 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

Table of n, a(n) for n=1..9.

FORMULA

a(n) = A139228(n)/2.

MATHEMATICA

Differences[Select[Range[10000], DivisorSigma[1, #] == 2# &]]/2 (* Alonso del Arte, Mar 05 2020 *)

CROSSREFS

Cf. A000396, A139228, A139230, A139231, A139232, A139233, A139234, A139235, A139236, A139237.

Sequence in context: A033864 A142120 A252893 * A266652 A142672 A158297

Adjacent sequences:  A139226 A139227 A139228 * A139230 A139231 A139232

KEYWORD

nonn

AUTHOR

Omar E. Pol, Apr 19 2008

EXTENSIONS

a(6)-a(9) from A139228(n)/2 by Jinyuan Wang, Mar 04 2020

STATUS

approved

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Last modified June 21 19:12 EDT 2021. Contains 345365 sequences. (Running on oeis4.)