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A106271 Row sums of number triangle A106270. 1
1, 0, -2, -7, -21, -63, -195, -624, -2054, -6916, -23712, -82498, -290510, -1033410, -3707850, -13402695, -48760365, -178405155, -656043855, -2423307045, -8987427465, -33453694485, -124936258125, -467995871775, -1757900019099, -6619846420551, -24987199492703 (list; graph; refs; listen; history; internal format)
OFFSET

0,3

FORMULA

G.f.: c(x)sqrt(1-4x)/(1-x), c(x) the g.f. of A000108; a(n)=sum{k=0..n, 2*0^(n-k)-C(n-k)}.

a(n) = 2 - A014137(n). a(n) = 1 - A014138(n-1) for n>0. - Alexander Adamchuk (alex(AT)kolmogorov.com), Feb 23 2007

MATHEMATICA

Table[1 - Sum[(2n)!/n!/(n+1)!, {n, 1, k}], {k, 0, 30}] - Alexander Adamchuk (alex(AT)kolmogorov.com), Feb 23 2007

CROSSREFS

Cf. A014138, A014137 = Partial sums of Catalan numbers (A000108).

Sequence in context: A007050 A005666 A159972 * A027990 A037520 A052911

Adjacent sequences:  A106268 A106269 A106270 * A106272 A106273 A106274

KEYWORD

easy,sign

AUTHOR

Paul Barry (pbarry(AT)wit.ie), Apr 28 2005

EXTENSIONS

More terms from Alexander Adamchuk (alex(AT)kolmogorov.com), Feb 23 2007

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Last modified February 17 07:41 EST 2012. Contains 205998 sequences.