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A039809 a(n), n>1, doubles under transform T where Ta is matrix product of Partition Triangle A008284 with a. +0
4
1, 1, 2, 5, 12, 32, 83, 223, 594, 1600, 4297, 11589, 31216, 84212, 227091, 612712, 1652913, 4459962, 12033405, 32469682, 87611105, 236402465, 637884103, 1721218224, 4644392797, 12532091909, 33815653370, 91245738923 (list; graph; listen)
OFFSET

1,3

FORMULA

a(1)=1. a(n) = sum {i=1 to n-1} A008284(n, i)*a(i).

a(n+1)= Sum{k, 0<=k<=n}A081719(n,k) . - Philippe DELEHAM (kolotoko(AT)wanadoo.fr), Sep 30 2006

EXAMPLE

So a(7) = T(7,1)*a(1) + T(7,2)*a(2) + ... + T(7,6)*a(6) = 1*1 + 3*1 + 4*2 + 3*5 + 2*12 + 1*32 = 1 + 3 + 8 + 15 + 24 + 32 = 83.

CROSSREFS

Sequence in context: A090826 A132441 A000840 this_sequence A002838 A076822 A014326

Adjacent sequences: A039806 A039807 A039808 this_sequence A039810 A039811 A039812

KEYWORD

nonn,eigen

AUTHOR

Christian G. Bower (bowerc(AT)usa.net), Feb 15 1999.

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Last modified July 19 08:04 EDT 2008. Contains 142098 sequences.


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