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A069071 (2n+1)*((2n+1)^4+4). 0
5, 255, 3145, 16835, 59085, 161095, 371345, 759435, 1419925, 2476175, 4084185, 6436435, 9765725, 14349015, 20511265, 28629275, 39135525, 52522015, 69344105, 90224355, 115856365, 147008615, 184528305, 229345195, 282475445, 345025455 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,1

LINKS

Table of n, a(n) for n=0..25.

FORMULA

Pi=16*sum(n=0, inf, (-1)^n/a(n))

CROSSREFS

Sequence in context: A332125 A308652 A002770 * A275930 A181397 A283039

Adjacent sequences:  A069068 A069069 A069070 * A069072 A069073 A069074

KEYWORD

easy,nonn

AUTHOR

Benoit Cloitre, Apr 05 2002

STATUS

approved

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Last modified February 18 09:15 EST 2020. Contains 332011 sequences. (Running on oeis4.)