Search: id:A073178 Results 1-1 of 1 results found. %I A073178 %S A073178 1,2,13,180,4266,153180,7725510,519629040,44880355800,4835536256880, %T A073178 635221698211800,99872627051181600,18507444606249152400, %U A073178 3990439472567239692000,990119486841576670378800 %N A073178 a(n) = n!^2 times coefficient of x^n in e^(x*(3-x)/2/(1-x))/(1-x)^(1/ 2). %D A073178 R. P. Stanley, Enumerative Combinatorics, Cambridge, Vol. 2, 1999; see Problem 5.65(b). %F A073178 e^(x*(3-x)/2/(1-x))/(1-x)^(1/2) = Sum_{n>=0} a(n)*x^n/n!^2. - Vladeta Jovovic (vladeta(AT)eunet.rs), Aug 01 2006 %o A073178 (PARI) a(n)=if(n<0,0,n!^2*polcoeff(exp(x*(3-x)/2/(1-x)+x*O(x^n))/sqrt(1-x+x*O(x^n)), n)) %Y A073178 Cf. A049088. %Y A073178 Sequence in context: A006905 A119400 A137610 this_sequence A062156 A049512 A003507 %Y A073178 Adjacent sequences: A073175 A073176 A073177 this_sequence A073179 A073180 A073181 %K A073178 nonn %O A073178 0,2 %A A073178 Michael Somos, Jul 19 2002 Search completed in 0.001 seconds