OFFSET
1,3
LINKS
Andrew Howroyd, Table of n, a(n) for n = 1..1275 (rows 1..50)
EXAMPLE
The T(3,2) = 9 pairs of set partitions:
{{1},{2,3}} {{1},{2,3}}
{{1},{2,3}} {{1,2,3}}
{{1,2},{3}} {{1,2},{3}}
{{1,2},{3}} {{1,2,3}}
{{1,3},{2}} {{1,3},{2}}
{{1,3},{2}} {{1,2,3}}
{{1,2,3}} {{1},{2,3}}
{{1,2,3}} {{1,2},{3}}
{{1,2,3}} {{1,3},{2}}
Triangle begins:
1
1 3
1 9 15
1 21 90 113
1 45 375 1130 1153
1 93 1350 7345 17295 15125
MATHEMATICA
Table[StirlingS2[n, k]*Sum[StirlingS1[k, i]*BellB[i]^2, {i, k}], {n, 10}, {k, n}]
PROG
(PARI) row(n) = {my(b=Vec(serlaplace(exp(exp(x + O(x*x^n))-1)-1))); vector(n, k, stirling(n, k, 2)*sum(i=1, k, stirling(k, i, 1)*b[i]^2))}
{ for(n=1, 10, print(row(n))) } \\ Andrew Howroyd, Jan 19 2023
CROSSREFS
KEYWORD
nonn,tabl
AUTHOR
Gus Wiseman, Aug 25 2018
STATUS
approved