2,2

E.g.f.: (hypergeom([1/3, 1/2], [], 36*x) - 3*hypergeom([1/6, 1/3], [], 36*x) + 2)/(3!*16).

a(n)= (2^n)*product(3*j+1, j=0..n-1)*(-3*product(6*j+1, j=0..n-1) + product(6*j+3, j=0..n-1))/(3!*16), n>=2. From eq.12 of the Blasiak et al. reference given in A078740 with r=8, s=2, k=3.

a(n)=(2^(2*n-5))*(3^(2*n-1))*risefac(1/3, n)*(-3*risefac(1/6, n) + risefac(1/2, n)), n>=2, with risefac(x, n)=Pochhammer(x, n).

Cf. A091551 (second column of (7, 2)-Stirling2 array).

Sequence in context: A118284 A118843 A053172 this_sequence A159004 A031782 A060980

Adjacent sequences: A091549 A091550 A091551 this_sequence A091553 A091554 A091555

nonn,easy

Wolfdieter Lang (wolfdieter.lang_AT_physik_DOT_uni-karlsruhe_DOT_de), Feb 13 2004