OFFSET
0,7
FORMULA
Euler transform of period 6 sequence [ 0, 1, 1, 0, 0, 0, ...]. - Michael Somos, Feb 09 2012
G.f.: 1 / (Product_{k>0} (1 - x^(6*k - 4)) * (1 - x^(6*k - 3))). - Michael Somos, Feb 09 2012
a(n) ~ exp(Pi*sqrt(2*n)/3) * Gamma(1/3) / (4 * 2^(1/3) * sqrt(3) * Pi^(2/3) * n^(2/3)). - Vaclav Kotesovec, Aug 27 2015
MATHEMATICA
nmax = 100; CoefficientList[Series[Product[1/((1 - x^(6k+2))*(1 - x^(6k+3))), {k, 0, nmax}], {x, 0, nmax}], x] (* Vaclav Kotesovec, Aug 27 2015 *)
PROG
(PARI) {a(n) = if( n<0, 0, polcoeff( 1 / prod( k=1, (n+4)\6, (1 - x^(6*k - 4)) * (1 - x^(6*k - 3)), 1 + x * O(x^n)), n))} /* Michael Somos, Feb 09 2012 */
CROSSREFS
KEYWORD
nonn
AUTHOR
STATUS
approved