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%I #18 Feb 06 2020 08:19:04
%S 0,1,1,1,2,2,2,4,2,2,3,2,2,4,3,4,6,3,2,3,3,5,6,6,4,9,3,3,2,3,3,4,5,3,
%T 5,4,2,3,3,4,2,7,5,7,7,5,5,6,6,4,5,8,9,4,5,6,3,3,7,6,8,7,7,4,5,4,4,7,
%U 7,9,11,5,8,7,7,6,7,7,8,12,4,7,6,6,4,8,7,4,10,7,7,6,6,7,5,5,6,8,7,9,10,5,7
%N Number of prime divisors (counted with multiplicity) of the central trinomial coefficients (A002426).
%C First occurrence of k: 1,2,5,11,8,22,17,42,52,26,89,71,80,....
%H Amiram Eldar, <a href="/A102445/b102445.txt">Table of n, a(n) for n = 1..218</a>
%H Eric Weisstein's World of Mathematics, <a href="http://mathworld.wolfram.com/TrinomialCoefficient.html">Trinomial Coefficient.</a>.
%F a(n) = A001222(A002426(n)). - _Amiram Eldar_, Feb 06 2020
%t bigomega[n_Integer] := Plus @@ Last /@ FactorInteger[n]; tn[n_] := Sum[Binomial[n, k]*Binomial[n - k, k], {k, 0, n/2}]; Table[bigomega[tn[n]], {n, 103}] (* _Robert G. Wilson v_, Feb 21 2005 *)
%Y Cf. A001222, A002426.
%K nonn
%O 1,5
%A _Jonathan Vos Post_, Feb 21 2005
%E Edited and extended by _Robert G. Wilson v_, Feb 21 2005
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