A180624 - OEIS

A180624

Partials sums of A090615.

1264460, 3379784, 6164364, 11102500, 18271604, 36320580, 54976960, 83135125, 129857825, 210986457, 385264277, 594788487, 924792067, 1423007483, 2659409715, 4458691045, 6846467595, 9563962830, 12443660134, 16149431959

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OFFSET

1,1

COMMENTS

Partials sums of smallest member of sociable quadruples. Primes in this partial sum begin: 924792067, 16149431959.

LINKS

Table of n, a(n) for n=1..20.

Eric W. Weisstein, Sociable Numbers

FORMULA

a(n) = sum[i=1..n] A090615(i).

EXAMPLE

a(13) = 1264460 + 2115324 + 2784580 + 4938136 + 7169104 + 18048976 + 18656380 + 28158165 + 46722700 + 81128632 + 174277820 + 209524210 + 330003580 = 924792067 is prime.

CROSSREFS

Cf. A090615.

Sequence in context: A072892 A090615 A222975 * A081430 A254026 A254019

Adjacent sequences: A180621 A180622 A180623 * A180625 A180626 A180627

KEYWORD

nonn,less

AUTHOR

Jonathan Vos Post, Sep 13 2010

STATUS

approved