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A018218
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Sum(C(j)*(n-j)*4^(n-j-1),j=0..n-1), C = Catalan numbers.
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6
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0, 1, 9, 58, 325, 1686, 8330, 39796, 185517, 848830, 3827230, 17053356, 75249954, 329353948, 1431575220, 6185613032, 26589395581, 113780713806, 484945025942, 2059546425340, 8719018250838, 36805967321684
(list; graph; refs; listen; history; internal format)
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OFFSET
| 0,3
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LINKS
| Vincenzo Librandi, Table of n, a(n) for n = 0..173
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FORMULA
| a(n)=(n+1)*(4^n-binomial(2*n+1, n))/2; G.f.: x*c(x)/(1-4*x)^2, where c(x) = g.f. for Catalan numbers A000108; also convolution of A000346(n-1), n >= 0, where A000346(-1)=0, with A000302 (powers of 4) - from Wolfdieter Lang (wolfdieter.lang(AT)physik.uni-karlsruhe.de).
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PROG
| (MAGMA) [(n+1)*(4^n-Binomial(2*n+1, n))/2: n in [0..25]]; // Vincenzo Librandi, Jun 09 2011
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CROSSREFS
| Sequence in context: A044528 A027174 A099624 * A026750 A009034 A026377
Adjacent sequences: A018215 A018216 A018217 * A018219 A018220 A018221
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KEYWORD
| nonn
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AUTHOR
| N. J. A. Sloane (njas(AT)research.att.com), Peter Winkler (pw(AT)bell-labs.com)
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