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This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

A356718 T(n,k) is the total number of prime factors, counted with multiplicity, of k!*(n-k)!, for 0 <= k <= n. Triangle read by rows.

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%I A356718 #89 Mar 04 2025 23:15:23
%S A356718 0,0,0,1,0,1,2,1,1,2,4,2,2,2,4,5,4,3,3,4,5,7,5,5,4,5,5,7,8,7,6,6,6,6,
%T A356718 7,8,11,8,8,7,8,7,8,8,11,13,11,9,9,9,9,9,9,11,13,15,13,12,10,11,10,11,
%U A356718 10,12,13,15,16,15,14,13,12,12,12
%N A356718 T(n,k) is the total number of prime factors, counted with multiplicity, of k!*(n-k)!, for 0 <= k <= n. Triangle read by rows.
%C A356718 k!*(n-k)! is the denominator in binomial(n,k) = n!/(k!*(n-k)!) and all prime factors in the denominator cancel to leave an integer, so that T(n,k) = A022559(n) - A132896(n,k).
%H A356718 Dario T. de Castro, <a href="/A356718/b356718.txt">Rows n = 0..140 of triangle, flattened</a>
%F A356718 T(n,k) = bigomega(k!*(n-k)!), where 0 <= k <= n.
%F A356718 T(n,0) = T(n,n) = A022559(n).
%e A356718 Triangle begins:
%e A356718   n\k| 0  1  2  3  4  5  6  7
%e A356718   ---+--------------------------------------
%e A356718    0 | 0
%e A356718    1 | 0, 0;
%e A356718    2 | 1, 0, 1;
%e A356718    3 | 2, 1, 1, 2;
%e A356718    4 | 4, 2, 2, 2, 4;
%e A356718    5 | 5, 4, 3, 3, 4, 5;
%t A356718 T[n_,k_]:=PrimeOmega[Factorial[k]*Factorial[n-k]];
%t A356718 tab=Flatten[Table[T[n,k],{n,0,10},{k,0,n}]]
%Y A356718 Cf. A007318, A001222, A022559, A132896, A303279.
%K A356718 nonn,tabl,easy,look
%O A356718 0,7
%A A356718 _Dario T. de Castro_, Aug 24 2022