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A389718
a(n) = Sum_{k=0..floor(5*n/14)} binomial(k,5*n-14*k).
2
1, 0, 0, 1, 0, 0, 1, 0, 0, 1, 0, 0, 1, 0, 1, 1, 0, 6, 1, 0, 21, 1, 0, 56, 1, 0, 126, 1, 1, 252, 1, 11, 462, 1, 66, 792, 1, 286, 1287, 1, 1001, 2002, 2, 3003, 3003, 17, 8008, 4368, 137, 19448, 6188, 817, 43758, 8568, 3877, 92378, 11629, 15505, 184756, 15525, 54265, 352716, 20580
OFFSET
0,18
LINKS
Index entries for linear recurrences with constant coefficients, signature (0,0,5,0,0,-10,0,0,10,0,0,-5,0,1,1).
FORMULA
G.f.: (1-x^3)^4 / ((1-x^3)^5 - x^14).
a(n) = 5*a(n-3) - 10*a(n-6) + 10*a(n-9) - 5*a(n-12) + a(n-14) + a(n-15).
PROG
(PARI) my(N=70, x='x+O('x^N)); Vec((1-x^3)^4/((1-x^3)^5-x^14))
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Seiichi Manyama, Jan 08 2026
STATUS
approved