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A242024 Decimal expansion of Sum(n>=1, (-1)^(n + 1)*6/(n*(n + 1)*(n + 2)). 3
8, 1, 7, 7, 6, 6, 1, 6, 6, 7, 1, 9, 3, 4, 3, 7, 1, 3, 0, 0, 6, 7, 8, 5, 4, 5, 7, 4, 9, 8, 1, 1, 8, 8, 1, 6, 9, 0, 6, 0, 0, 1, 6, 1, 2, 3, 2, 3, 0, 6, 3, 0, 4, 9, 4, 4, 8, 1, 6, 0, 1, 1, 3, 9, 2, 0, 7, 2, 3, 4, 6, 3, 6, 3, 6, 3, 3, 6, 5, 8, 7, 2, 7, 0, 3, 5, 9, 9, 2, 3, 9, 5, 7 (list; constant; graph; refs; listen; history; text; internal format)
OFFSET

0,1

COMMENTS

The sum of terms of the inverse of Binomial(n,3) for n>=3, (or A000292(n), for n>=1) with alternating signs.

Also see A242023.

LINKS

Table of n, a(n) for n=0..92.

FORMULA

Equals 12*log(2) - 15/2.

EXAMPLE

0.8177661667193437130067854...

MATHEMATICA

RealDigits[Chop[Sum[N[(-1)^(n+1)*6/(n*(n+1)*(n+2)), 150], {n, 1, Infinity}]], 10, 120][[1]] (* Harvey P. Dale, Jun 02 2016 *)

PROG

(PARI) 12*log(2) - 15/2 \\ Michel Marcus, Aug 13 2014

(PARI) sumalt(n=1, (-1)^(n + 1)*6/(n*(n + 1)*(n + 2))) \\ Michel Marcus, Aug 14 2014

CROSSREFS

Cf. A242023, A000217, A000292, A000332, A002162.

Sequence in context: A245280 A200585 A200277 * A159642 A246750 A234614

Adjacent sequences:  A242021 A242022 A242023 * A242025 A242026 A242027

KEYWORD

nonn,cons

AUTHOR

Richard R. Forberg, Aug 11 2014

EXTENSIONS

Prior Mathematica program replaced by Harvey P. Dale, Jun 02 2016

STATUS

approved

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Last modified August 22 12:39 EDT 2017. Contains 290946 sequences.