Search: id:A002803 Results 1-1 of 1 results found. %I A002803 M4980 N2140 %S A002803 1,15,140,1050,6930,42042,240240,1312740,6928350,35565530,178474296, %T A002803 878850700,4259045700,20359174500,96172862400,449608131720, %U A002803 2082743551350,9569730173850,43651400793000,197809768856700 %N A002803 (2n+4)!/(4!n!(n+1)!). %D A002803 N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence). %D A002803 N. J. A. Sloane, A Handbook of Integer Sequences, Academic Press, 1973 (includes this sequence). %D A002803 C. Jordan, Calculus of Finite Differences. Budapest, 1939, p. 449. %D A002803 Walsh, T. R. S.; Lehman, A. B.; Counting rooted maps by genus. III: Nonseparable maps. J. Combinatorial Theory Ser. B 18 (1975), 222-259. %p A002803 seq(binomial(2*i,i)*binomial(i,i-2)*i/12, i=2..21); - Zerinvary Lajos (zerinvarylajos(AT)yahoo.com), Jan 06 2007 %t A002803 a[n_]:=(2*n+4)!/(4!*n!*(n+1)!); [From Vladimir Orlovsky (4vladimir(AT)gmail.com), Dec 13 2008] %Y A002803 Sequence in context: A027802 A133716 A035330 this_sequence A056281 A000481 A055903 %Y A002803 Adjacent sequences: A002800 A002801 A002802 this_sequence A002804 A002805 A002806 %K A002803 nonn,easy %O A002803 0,2 %A A002803 N. J. A. Sloane (njas(AT)research.att.com). %E A002803 More terms from Emeric Deutsch (deutsch(AT)duke.poly.edu), Dec 17 2003 Search completed in 0.001 seconds