login
The OEIS is supported by the many generous donors to the OEIS Foundation.

 

Logo
Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A157399 A partition product of Stirling_2 type [parameter k = -3] with biggest-part statistic (triangle read by rows). 10

%I #2 Mar 30 2012 17:27:11

%S 1,1,3,1,9,15,1,45,60,105,1,165,600,525,945,1,855,5250,6300,5670,

%T 10395,1,3843,39900,91875,79380,72765,135135,1,21819,391440,1164975,

%U 1323000,1164240,1081080,2027025,1

%N A partition product of Stirling_2 type [parameter k = -3] with biggest-part statistic (triangle read by rows).

%C Partition product of prod_{j=0..n-1}((k + 1)*j - 1) and n! at k = -3,

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

%C Underlying partition triangle is A134144.

%C Same partition product with length statistic is A035342.

%C Diagonal a(A000217) = A001147.

%C Row sum is A049118.

%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/stirling2partitions.html"> Generalized Stirling_2 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-1}(-2*j - 1).

%Y Cf. A157396, A157397, A157398, A157400, A080510, A157401, A157402, A157403, A157404, A157405

%K easy,nonn,tabl

%O 1,3

%A _Peter Luschny_, Mar 09 2009, Mar 14 2009

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recents
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified April 19 21:09 EDT 2024. Contains 371798 sequences. (Running on oeis4.)