|
|
A157399
|
|
A partition product of Stirling_2 type [parameter k = -3] with biggest-part statistic (triangle read by rows).
|
|
10
|
|
|
1, 1, 3, 1, 9, 15, 1, 45, 60, 105, 1, 165, 600, 525, 945, 1, 855, 5250, 6300, 5670, 10395, 1, 3843, 39900, 91875, 79380, 72765, 135135, 1, 21819, 391440, 1164975, 1323000, 1164240, 1081080, 2027025, 1
(list;
table;
graph;
refs;
listen;
history;
text;
internal format)
|
|
|
OFFSET
|
1,3
|
|
COMMENTS
|
Partition product of prod_{j=0..n-1}((k + 1)*j - 1) and n! at k = -3,
summed over parts with equal biggest part (see the Luschny link).
Underlying partition triangle is A134144.
Same partition product with length statistic is A035342.
|
|
LINKS
|
|
|
FORMULA
|
T(n,0) = [n = 0] (Iverson notation) and for n > 0 and 1 <= m <= n
T(n,m) = Sum_{a} M(a)|f^a| where a = a_1,..,a_n such that
1*a_1+2*a_2+...+n*a_n = n and max{a_i} = m, M(a) = n!/(a_1!*..*a_n!),
f^a = (f_1/1!)^a_1*..*(f_n/n!)^a_n and f_n = product_{j=0..n-1}(-2*j - 1).
|
|
CROSSREFS
|
|
|
KEYWORD
|
|
|
AUTHOR
|
|
|
STATUS
|
approved
|
|
|
|