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 A227469 a(n) = binomial((n+1)^2, n) * (2*n+1) / (n+1)^2 for n>=0. 0
 1, 3, 20, 245, 4554, 115192, 3709992, 145597545, 6750522350, 361424043596, 21958844607336, 1493260499980119, 112400273159533800, 9279595605913516080, 833858283261973732944, 81027308003810095983825, 8466793463341565312119830, 946776552967215128481968260, 112816032067073649248569919400 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,2 LINKS FORMULA a(n) = (2*n+1)*A143669(n). EXAMPLE G.f.: A(x) = 1 + 3*x + 20*x^2 + 245*x^3 + 4554*x^4 + 115192*x^5 +... PROG (PARI) {a(n)=binomial((n+1)^2, n)*(2*n+1)/(n+1)^2} for(n=0, 20, print1(a(n), ", ")) CROSSREFS Cf. A143669. Sequence in context: A237431 A237652 A256018 * A262208 A324955 A183607 Adjacent sequences:  A227466 A227467 A227468 * A227470 A227471 A227472 KEYWORD nonn AUTHOR Paul D. Hanna, Aug 23 2013 STATUS approved

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Last modified October 17 16:51 EDT 2019. Contains 328120 sequences. (Running on oeis4.)