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A073156
Main diagonal sequence of triangle A073153.
4
1, 2, 9, 36, 156, 698, 3210, 15080, 72060, 349184, 1711869, 8475494, 42318018, 212843826, 1077391794, 5484472880, 28058940086, 144195777552, 744017466318, 3852968380624, 20019113126120, 104329129258596, 545214946753377
OFFSET
0,2
FORMULA
Convolution of sequence A073155: a(n)=sum{k=0..n} A073155(k)* A073155(n-k).
G.f.: 1/4*(1-(1-4*x*(1+x)^2)^(1/2))^2/x^2/(1+x)^4. - Vladeta Jovovic, Oct 10 2003
CROSSREFS
KEYWORD
easy,nonn
AUTHOR
Paul D. Hanna, Jul 29 2002
EXTENSIONS
More terms from Vladeta Jovovic, Oct 10 2003
STATUS
approved