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A102814
a(-1) = 1, a(n) = Sum_{k=0..n} A034851(n,k)*a(k-1) where A034851(n,k) are entries in Losanitsch's triangle.
1
1, 1, 2, 4, 11, 30, 103, 354, 1440, 5911, 27651, 131062, 690543, 3693765, 21585068, 128165652, 820859645, 5343318222, 37155889171, 262577578134, 1967281479508, 14975397597557, 120122032987319, 978625889818014, 8359402026954939, 72495015037575673, 656446920912518700
OFFSET
-1,3
LINKS
PROG
(PARI) \\ here T(n, k) is A034851(n, k).
T(n, k) = {(1/2)*(binomial(n, k) + binomial(n%2, k%2) * binomial(n\2, k\2))}
seq(n)={my(a=vector(n+1)); a[1]=1; for(n=1, n, a[n+1]=sum(k=1, n, a[k]*T(n-1, k-1))); a} \\ Andrew Howroyd, Nov 06 2019
CROSSREFS
Cf. A034851.
Sequence in context: A148158 A148159 A275310 * A193059 A034770 A276687
KEYWORD
nonn
AUTHOR
Gerald McGarvey, Feb 26 2005
EXTENSIONS
Terms a(12) and beyond from Andrew Howroyd, Nov 06 2019
STATUS
approved