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A361277
Square array T(n,k), n >= 0, k >= 0, read by antidiagonals downwards, where T(n,k) = n! * Sum_{j=0..n} binomial(k*j,n-j)/j!.
4
1, 1, 1, 1, 1, 1, 1, 1, 3, 1, 1, 1, 5, 7, 1, 1, 1, 7, 19, 25, 1, 1, 1, 9, 37, 97, 81, 1, 1, 1, 11, 61, 241, 581, 331, 1, 1, 1, 13, 91, 481, 1981, 3661, 1303, 1, 1, 1, 15, 127, 841, 4881, 17551, 26335, 5937, 1, 1, 1, 17, 169, 1345, 10001, 55321, 171697, 202049, 26785, 1
OFFSET
0,9
FORMULA
E.g.f. of column k: exp(x * (1+x)^k).
T(0,k) = 1; T(n,k) = (n-1)! * Sum_{j=1..n} j * binomial(k,j-1) * T(n-j,k)/(n-j)!.
EXAMPLE
Square array begins:
1, 1, 1, 1, 1, 1, ...
1, 1, 1, 1, 1, 1, ...
1, 3, 5, 7, 9, 11, ...
1, 7, 19, 37, 61, 91, ...
1, 25, 97, 241, 481, 841, ...
1, 81, 581, 1981, 4881, 10001, ...
PROG
(PARI) T(n, k) = n!*sum(j=0, n, binomial(k*j, n-j)/j!);
CROSSREFS
Columns k=0..4 give A000012, A047974, A361278, A361279, A361280.
Main diagonal gives A361281.
Cf. A293012.
Sequence in context: A112475 A347232 A307855 * A300853 A293012 A341033
KEYWORD
nonn,tabl
AUTHOR
Seiichi Manyama, Mar 06 2023
STATUS
approved