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A033467 Partial sums of sequence {1/(i^2+1): i=0..n} (numerators). 1
1, 3, 17, 9, 158, 4193, 157351, 397466, 400611, 33054527, 3355270077, 102758999311, 2990338571904, 5998294800553, 1184659077355591, 67080741701688404, 17273086483161957653, 34605257914722575451, 6931595973735660593, 628166167374857855769, 252204770011462567264474 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,2

LINKS

Table of n, a(n) for n=0..20.

EXAMPLE

Take the sequence

1, 1/2, 1/5, 1/10, 1/17, 1/26, 1/37, 1/50, 1/65, 1/82, 1/101, 1/122, 1/145, 1/170, 1/197, 1/226, ...,

take partial sums:

1, 3/2, 17/10, 9/5, 158/85, 4193/2210, 157351/81770, 397466/204425, 400611/204425, 33054527/16762850, 3355270077/1693047850, ...,

take numerators:

1, 3, 17, 9, 158, 4193, 157351, 397466, 400611, 33054527, 3355270077, 102758999311, ...

MATHEMATICA

Accumulate[Table[1/(n^2+1), {n, 0, 20}]]//Numerator (* Harvey P. Dale, Jan 20 2020 *)

PROG

(PARI) for(n=0, 20, print1(numerator(sum(k=0, n, 1/(k^2+1))), ", ")) \\ Hugo Pfoertner, Apr 27 2020

CROSSREFS

Denominators are in A033468.

Sequence in context: A273273 A273249 A273303 * A096475 A088122 A273702

Adjacent sequences:  A033464 A033465 A033466 * A033468 A033469 A033470

KEYWORD

nonn

AUTHOR

N. J. A. Sloane.

STATUS

approved

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Last modified January 23 23:56 EST 2021. Contains 340398 sequences. (Running on oeis4.)