The OEIS Foundation is supported by donations from users of the OEIS and by a grant from the Simons Foundation.

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A212273 a(n) = n * A000699(n). 1
 1, 2, 12, 108, 1240, 16980, 267624, 4750872, 93615408, 2026018980, 47764893000, 1218621868200, 33459133580496, 983950866169544, 30862364045494800, 1028656519404191280, 36312294166359724128, 1353561646509338629572, 53133041579508472510728 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 LINKS FORMULA a(n) = [x^n] A178685(x)^n. a(n) ~ n^(n+1) * 2^(n+1/2) / exp(n+1). - Vaclav Kotesovec, Feb 22 2014 EXAMPLE G.f. = x + 2*x^2 + 12*x^3 + 108*x^4 + 1240*x^5 + 16980*x^6 + 267624*x^7 + 4750872*x^8 + ... PROG (PARI) {a(n) = my(A); A = O(x); for(i=1, n, A = x + A * (2 * x * A' - A)); n * polcoeff(A, n)}; CROSSREFS Cf. A000699, A178685. Sequence in context: A301411 A217803 A177409 * A055897 A210997 A052563 Adjacent sequences:  A212270 A212271 A212272 * A212274 A212275 A212276 KEYWORD nonn AUTHOR Michael Somos, May 12 2012 STATUS approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

Last modified May 17 22:15 EDT 2021. Contains 343992 sequences. (Running on oeis4.)