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A134238
Row sums of triangle A134237.
4
1, 5, 14, 28, 47, 71, 100, 134, 173, 217, 266, 320, 379, 443, 512, 586, 665, 749, 838, 932, 1031, 1135, 1244, 1358, 1477, 1601, 1730, 1864, 2003, 2147, 2296, 2450, 2609, 2773, 2942, 3116, 3295, 3479, 3668, 3862, 4061, 4265, 4474, 4688, 4907, 5131, 5360, 5594, 5833, 6077
OFFSET
1,2
FORMULA
Binomial transform of (1, 4, 5, 0, 0, 0, ...).
a(n) = a(n-1) + 5*n - 6 (with a(1)=1). - Vincenzo Librandi, Nov 23 2010
a(n) = (5*n^2 - 7*n + 4)/2. - Charles R Greathouse IV, Jun 17 2017
From Elmo R. Oliveira, Feb 08 2025: (Start)
G.f.: x*(2*x^2 + 2*x + 1)/(1-x)^3.
E.g.f.: exp(x)*(5*x^2 - 2*x + 4)/2 - 2.
a(n) = 3*a(n-1) - 3*a(n-2) + a(n-3) for n >= 4. (End)
PROG
(PARI) a(n)=(5*n^2-7*n+4)/2 \\ Charles R Greathouse IV, Jun 17 2017
CROSSREFS
Cf. A134237.
Sequence in context: A055454 A301294 A073347 * A024800 A005586 A197058
KEYWORD
nonn,easy
AUTHOR
Gary W. Adamson, Oct 14 2007
EXTENSIONS
a(47) onwards from Andrew Howroyd, Feb 08 2025
STATUS
approved