A239545 Decimal expansion of Sum_{k>=0} (-1)^k/((2k+1)*(2k+3)*(2k+5)).

0, 5, 9, 3, 6, 5, 7, 4, 8, 3, 6, 5, 3, 9, 0, 8, 2, 1, 4, 7, 4, 4, 9, 7, 0, 8, 9, 5, 7, 6, 6, 0, 4, 5, 2, 7, 1, 9, 1, 3, 1, 2, 8, 4, 1, 5, 8, 8, 5, 5, 4, 8, 9, 4, 2, 8, 8, 5, 3, 4, 7, 4, 0, 7, 0, 5, 1, 4, 3, 7, 1, 7, 4, 5, 2, 4, 4, 2, 7, 9, 1, 4, 9, 5, 1, 7, 1, 0

Offset

0,2

Links

Table of n, a(n) for n=0..87.

L. B. W. Jolley, Summation of Series, Dover, 1961, p. 44 (series n. 240)

Formula

Equals Pi/8 - 1/3 = A019675 - A010701.

Equals Sum_{k>=1} 1/((4*k+1)*(4*k+3)) = Sum_{k>=1} 1/A001539(k). - Amiram Eldar, Jul 04 2020

Example

0.0593657483653908214744970895766045271913128415885548942885347407051...

Mathematica

RealDigits[Pi/8 - 1/3, 10, 90, -1][[1]]

Prog

(PARI) Pi/8-1/3 \\ Charles R Greathouse IV, May 05 2014

Crossrefs

Cf. A000796, A001539, A005408 (odd numbers) A021016 (Sum_{k>=0} 1/((2k+1)*(2k+3)*(2k+5))), A061550.

Sequence in context: A306883 A333155 A256500 * A228402 A154265 A198133

Adjacent sequences: A239542 A239543 A239544 * A239546 A239547 A239548

Keyword

nonn,cons,changed

Author

Bruno Berselli, Mar 21 2014

Status

approved