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!)
A157395 A partition product of Stirling_1 type [parameter k = 5] with biggest-part statistic (triangle read by rows). 11

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

%S 1,1,5,1,15,20,1,105,80,60,1,425,1200,300,120,1,3075,10400,5400,720,

%T 120,1,15855,102200,75600,15120,840,0,1,123515,1149120,907200,241920,

%U 20160,0,0,1,757755,12783680,13426560,3719520,362880

%N A partition product of Stirling_1 type [parameter k = 5] 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 = 5,

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

%C Underlying partition triangle is A144879.

%C Same partition product with length statistic is A049411.

%C Diagonal a(A000217(n)) = falling_factorial(5,n-1), row in A008279

%C Row sum is A049428.

%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+7).

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

%K easy,nonn,tabl

%O 1,3

%A _Peter Luschny_, Mar 07 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 25 01:35 EDT 2024. Contains 371964 sequences. (Running on oeis4.)