Search: id:A052468 Results 1-1 of 1 results found. %I A052468 %S A052468 1,3,5,35,63,77,429,6435,12155,46189,88179,676039,1300075,5014575, %T A052468 646323,300540195,583401555,756261275,4418157975,6892326441, %U A052468 22427411435,263012370465,514589420475,2687300306925,15801325804719 %N A052468 Numerators in the Taylor series for arccosh(x)-ln(2x). %C A052468 A055786 is the preferred version of this sequence. %H A052468 Eric Weisstein's World of Mathematics, Link to a section of The World of Mathematics. %H A052468 Eric Weisstein's World of Mathematics, Inverse Hyperbolic Cosecant %H A052468 Eric Weisstein's World of Mathematics, Inverse Hyperbolic Cosine %H A052468 Eric Weisstein's World of Mathematics, Inverse Hyperbolic Sine %F A052468 a(n) / A052469(n) = A001147(n) / ( A000165(n) *2*n ). E.g. a(6) = 77 = 1*3*5*7*9*11 / gcd( 1*3*5*7*9*11, 2*4*6*8*10*12*12 ) %F A052468 Contribution from Johannes W. Meijer (meijgia(AT)hotmail.com), Jul 06 2009: (Start) %F A052468 a(n) = numer((2*n-1)!/(2^(2*n)*(n!)^2)) %F A052468 (End) %e A052468 I*Pi/2 - arccosh(x) = I*x + 1/6*I*x^3 + 3/40*I*x^5 + 5/112*I*x^7 + 35/ 1152*I*x^9 + 63/2816*I*x^11 + 231/13312*I*x^13 + 143/10240*I*x^15 + 6435/557056*I*x^17 + ... %e A052468 0, 1, 0, 1/6, 0, 3/40, 0, 5/112, 0, 35/1152, 0, 63/2816, 0, 231/13312, 0, 143/10240, 0, 6435/557056, 0, 12155/1245184, 0, 46189/5505024, 0, ... = A052468/A052469 %Y A052468 See A055786 for further information. %Y A052468 A52468(n)/A52469(n)=(1/(2*n))*A001790(n)/A046161(n) for n=>1. %Y A052468 Contribution from Johannes W. Meijer (meijgia(AT)hotmail.com), Jul 06 2009: (Start) %Y A052468 Equals A162441(n+1)/(2n+1) for n=>1. %Y A052468 (End) %Y A052468 Sequence in context: A103010 A068111 A162444 this_sequence A055786 A001790 A057908 %Y A052468 Adjacent sequences: A052465 A052466 A052467 this_sequence A052469 A052470 A052471 %K A052468 nonn,easy,frac %O A052468 1,2 %A A052468 Eric Weisstein (eric(AT)weisstein.com) %E A052468 Updated May 22 2001 by Frank.Ellermann(AT)t-online.de %E A052468 Cross-references edited by Johannes W. Meijer (meijgia(AT)hotmail.com), Jul 05 2009 Search completed in 0.001 seconds