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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.
2
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, 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, 10, 12, 13, 15, 16, 15, 14, 13, 12, 12, 12
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OFFSET
0,7
COMMENTS
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).
LINKS
Dario T. de Castro,
Rows n = 0..140 of triangle, flattened
FORMULA
T(n,k) = bigomega(k!*(n-k)!), where 0 <= k <= n.
T(n,0) = T(n,n) =
A022559
(n).
EXAMPLE
Triangle begins:
n\k| 0 1 2 3 4 5 6 7
---+--------------------------------------
0 | 0
1 | 0, 0;
2 | 1, 0, 1;
3 | 2, 1, 1, 2;
4 | 4, 2, 2, 2, 4;
5 | 5, 4, 3, 3, 4, 5;
MATHEMATICA
T[n_, k_]:=PrimeOmega[Factorial[k]*Factorial[n-k]];
tab=Flatten[Table[T[n, k], {n, 0, 10}, {k, 0, n}]]
CROSSREFS
Cf.
A007318
,
A001222
,
A022559
,
A132896
,
A303279
.
Sequence in context:
A322134
A023504
A157905
*
A380203
A260931
A293819
Adjacent sequences:
A356715
A356716
A356717
*
A356719
A356720
A356721
KEYWORD
nonn
,
tabl
,
easy
,
look
AUTHOR
Dario T. de Castro
, Aug 24 2022
STATUS
approved