A139233 - OEIS

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A139233

Second differences of perfect numbers A000396, divided by 2.

11

223, 3582, 16767288, 4261388256, 60146251776, 1152921370926219264, 1329227995784915870021503368556314624, 95780971304118050988940697472320075563727548890218496

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OFFSET

1,1

LINKS

Paolo Xausa, Table of n, a(n) for n = 1..13

FORMULA

a(n) = A139230(n)/2.

MATHEMATICA

Differences[PerfectNumber[Range[12]], 2]/2 (* Paolo Xausa, Oct 20 2023 *)

CROSSREFS

Cf. A000396, A139228, A139229, A139230, A139231, A139232, A139234, A139235, A139236, A139237.

Sequence in context: A205273 A205266 A152834 * A205265 A153165 A094491

Adjacent sequences: A139230 A139231 A139232 * A139234 A139235 A139236

KEYWORD

nonn

AUTHOR

Omar E. Pol, Apr 19 2008

EXTENSIONS

a(5)-a(8) from Jinyuan Wang, Mar 04 2020

STATUS

approved