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A157391 A partition product of Stirling_1 type [parameter k = 1] with biggest-part statistic (triangle read by rows). 11

%I #6 Feb 12 2023 10:20:37

%S 1,1,1,1,3,0,1,9,0,0,1,25,0,0,0,1,75,0,0,0,0,1,231,0,0,0,0,0,1,763,0,

%T 0,0,0,0,0,1,2619,0,0,0,0,0,0,0,1,9495,0,0,0,0,0,0,0,0,1,35695,0,0,0,

%U 0,0,0,0,0,0,1,140151

%N A partition product of Stirling_1 type [parameter k = 1] with biggest-part statistic (triangle read by rows).

%C Partition product of prod_{j=0..n-2}(k-n+j+2) and n! at k = 1,

%C summed over parts with equal biggest part (see the Luschny link).

%C Underlying partition triangle is A144357.

%C Same partition product with length statistic is A049403.

%C Diagonal a(A000217(n)) = falling_factorial(1,n-1), row in A008279.

%C Row sum is A000085.

%H Peter Luschny, <a href="http://www.luschny.de/math/seq/CountingWithPartitions.html">Counting with Partitions</a>.

%H Peter Luschny, <a href="http://www.luschny.de/math/seq/stirling1partitions.html">Generalized Stirling_1 Triangles</a>.

%F T(n,0) = [n = 0] (Iverson notation) and for n > 0 and 1 <= m <= n

%F T(n,m) = Sum_{a} M(a)|f^a| where a = a_1,..,a_n such that

%F 1*a_1+2*a_2+...+n*a_n = n and max{a_i} = m, M(a) = n!/(a_1!*..*a_n!),

%F f^a = (f_1/1!)^a_1*..*(f_n/n!)^a_n and f_n = product_{j=0..n-2}(j-n+3).

%Y Cf. A157386, A157385, A157384, A157383, A157400, A157391, A157392, A157393, A157394, A157395

%K easy,nonn,tabl

%O 1,5

%A _Peter Luschny_, Mar 07 2009, Mar 14 2009

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Last modified March 28 14:38 EDT 2024. Contains 371254 sequences. (Running on oeis4.)