a(n) = (exp(k)*Gamma(1+n, k) - exp(-k)*Gamma(1+n, -k))/k! for k = 3.

A296661

a(n) = (exp(k)*Gamma(1+n, k) - exp(-k)*Gamma(1+n, -k))/k! for k = 3.

Terms

    a(0) =0a(1) =1a(2) =2a(3) =15a(4) =60a(5) =381a(6) =2286a(7) =16731a(8) =133848a(9) =1211193a(10) =12111930a(11) =133290279a(12) =1599483348a(13) =20793814965a(14) =291113409510

External references