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URL: https://oeis.org/A295476

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A295476
a(n) = (20*n)!*(9*n)!*(6*n)!/((18*n)!*(10*n)!*(4*n)!*(3*n)!).
2
1, 190, 95238, 54503020, 32989143110, 20598742103940, 13119794010495900, 8472058672655664024, 5526367916474032140870, 3632882290435237504630420, 2402807931482709593805719988, 1597125851104281978332538662760, 1065954690102347966626416591930140
OFFSET
0,2
FORMULA
G.f.: hypergeom([1/20, 3/20, 7/20, 9/20, 11/20, 13/20, 17/20, 19/20], [1/18, 5/18, 7/18, 1/2, 11/18, 13/18, 17/18], 10000000000/14348907*x).
a(n) = binomial(20*n,2*n)*binomial(6*n,2*n)*binomial(2*n,n)/(binomial(10*n,n)*binomial(3*n,n)). - Chai Wah Wu, Feb 16 2026
a(n) ~ 2^(10*n-1) * 5^(10*n) / (3^(15*n) * sqrt(Pi*n)). - Amiram Eldar, Feb 21 2026
MATHEMATICA
Table[Times@@(#!&/@(n{20, 9, 6}))/Times@@(#!&/@(n{18, 10, 4, 3})), {n, 0, 20}] (* Harvey P. Dale, May 12 2018 *)
PROG
(Python)
from math import comb
def A295476(n): return comb(20*n, 2*n)*comb(6*n, 2*n)*comb(2*n, n)//(comb(10*n, n)*comb(3*n, n)) # Chai Wah Wu, Feb 16 2026
CROSSREFS
Cf. A295431.
Sequence in context: A207198 A217343 A221112 * A238813 A103494 A104642
KEYWORD
nonn,easy
AUTHOR
Gheorghe Coserea, Nov 28 2017
STATUS
approved