0,2

a(n)=A027465(n+9,9) (O. Gerard's triangle).

With a different offset, number of n-permutations (n>=8) of 4 objects: u, v, z, x with repetition allowed, containing exactly eight (8) u's. Example: a(1)=27 because we have uuuuuuuuv, uuuuuuuuz, uuuuuuuux, uuuuuuuvu, uuuuuuuzu, uuuuuuuxu, uuuuuuvuu, uuuuuuzuu, uuuuuuxuu, uuuuuvuuu, uuuuuzuuu, uuuuuxuuu, uuuuvuuuu, uuuuzuuuu, uuuuxuuuu, uuuvuuuuu, uuuzuuuuu, uuuxuuuuu, uuvuuuuuu, uuzuuuuuu, uuxuuuuuu, uvuuuuuuu, uzuuuuuuu, uxuuuuuuu, vuuuuuuuu, zuuuuuuuu, xuuuuuuuu. - Zerinvary Lajos (zerinvarylajos(AT)yahoo.com), Jun 23 2008

a(n) = 3^n*binomial(n+8, 8); G.f. 1/(1-3*x)^9.

seq(binomial(n+8, 8)*3^n, n=0..18); - Zerinvary Lajos (zerinvarylajos(AT)yahoo.com), Jun 23 2008

A000244, A027465.

Sequence in context: A000535 A033280 A125462 this_sequence A022655 A096950 A125484

Adjacent sequences: A036219 A036220 A036221 this_sequence A036223 A036224 A036225

easy,nonn,new

Wolfdieter Lang (wolfdieter.lang(AT)physik.uni-karlsruhe.de)