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A091552
Second column (k=3) sequence of array A092077 ((8,2)-Stirling2) divided by 16.
2
1, 308, 154840, 121284800, 138146444800, 216595133081600, 448169865375232000, 1184352885735219200000, 3894384547720687820800000, 15599967808704696966348800000, 74806554280938737689393561600000
OFFSET
2,2
FORMULA
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).
CROSSREFS
Cf. A091551 (second column of (7, 2)-Stirling2 array).
Sequence in context: A053172 A343273 A337955 * A364936 A159004 A031782
KEYWORD
nonn,easy
AUTHOR
Wolfdieter Lang, Feb 13 2004
STATUS
approved