The OEIS Foundation is supported by donations from users of the OEIS and by a grant from the Simons Foundation.

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A294971 Denominators of the partial sums for the Catalan constant A006752: Sum_{k=0..n} ((-1)^k)/(2*k+1)^2, n >= 0. 4
 1, 9, 225, 11025, 99225, 12006225, 2029052025, 2029052025, 586396035225, 211688968716225, 211688968716225, 111983464450883025, 2799586611272075625, 25196279501448680625, 21190071060718340405625, 20363658289350325129805625 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,2 COMMENTS The corresponding numerators are given in A294970. There details are given. LINKS G. C. Greubel, Table of n, a(n) for n = 0..575 FORMULA a(n) = numerator(r(n)) with the rationals r(n) = Sum_{k=0..n} (-1)^k/(2*k+1)^2. For r(n) in terms of the Hurwitz Zeta function or the trigamma function see A294970. EXAMPLE See A294970. MATHEMATICA Table[Denominator[Sum[(-1)^k/(2*k+1)^2, {k, 0, n}]], {n, 0, 20}] (* Vaclav Kotesovec, Nov 15 2017 *) PROG (PARI) for(n=0, 20, print1(denominator(sum(k=0, n, (-1)^k/(2*k+1)^2)), ", ")) \\ G. C. Greubel, Aug 22 2018 (MAGMA) [Denominator((&+[(-1)^k/(2*k+1)^2: k in [0..n]])): n in [0..20]]; // G. C. Greubel, Aug 22 2018 CROSSREFS Cf. A006752, A294970. Sequence in context: A079727 A251579 A128492 * A001818 A095363 A138564 Adjacent sequences:  A294968 A294969 A294970 * A294972 A294973 A294974 KEYWORD nonn,frac,easy AUTHOR Wolfdieter Lang, Nov 15 2017 STATUS approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

Last modified September 28 02:36 EDT 2020. Contains 337392 sequences. (Running on oeis4.)