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A097022 a(n) = (sigma(2n^2)-3)/6. 3
0, 2, 6, 10, 15, 32, 28, 42, 60, 77, 66, 136, 91, 142, 201, 170, 153, 302, 190, 325, 370, 332, 276, 552, 390, 457, 546, 598, 435, 1007, 496, 682, 864, 767, 883, 1270, 703, 952, 1189, 1317, 861, 1852, 946, 1396, 1875, 1382, 1128, 2216, 1400, 1952, 1995, 1921 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

See A065764, A065765 and A097022.

LINKS

Harvey P. Dale, Table of n, a(n) for n = 1..1000

FORMULA

a(n) = (A065765(n)-3)/6 = A000203(A001105(n) - 3)/6.

MATHEMATICA

Table[(DivisorSigma[1, 2n^2]-3)/6, {n, 60}] (* Harvey P. Dale, Sep 12 2022 *)

PROG

(PARI) a(n) = (sigma(2*n^2) - 3)/6; \\ Michel Marcus, Dec 20 2013

CROSSREFS

Cf. A065764, A065765, A000203, A072682, A074627-A074630, A067051.

Sequence in context: A184426 A293408 A357387 * A137236 A124198 A032426

Adjacent sequences:  A097019 A097020 A097021 * A097023 A097024 A097025

KEYWORD

nonn

AUTHOR

Labos Elemer, Aug 24 2004

STATUS

approved

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Last modified September 27 12:49 EDT 2022. Contains 357057 sequences. (Running on oeis4.)