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A118403
Unsigned row sums of triangle A118401; a(n) = A118402(n^2-n+2), where A118402 is the row sums of triangle A118400.
3
1, 1, 3, 5, 9, 15, 23, 33, 45, 59, 75, 93, 113, 135, 159, 185, 213, 243, 275, 309, 345, 383, 423, 465, 509, 555, 603, 653, 705, 759, 815, 873, 933, 995, 1059, 1125, 1193, 1263, 1335, 1409, 1485, 1563, 1643, 1725, 1809, 1895, 1983, 2073, 2165, 2259, 2355
OFFSET
0,3
LINKS
FORMULA
G.f.: A(x) = (1-2*x+2*x^2)*(1+x^2)/(1-x)^3.
a(n) = A027688(n-2) for n > 1. - Jon Maiga, Jan 02 2019
MAPLE
seq(coeff(series((1-2*x+2*x^2)*(1+x^2)/(1-x)^3, x, n+1), x, n), n = 0 .. 55); # Muniru A Asiru, Jan 02 2019
MATHEMATICA
Join[{1, 1}, Table[n^2 + n + 3, {n, 0, 47}]] (* Jon Maiga, Jan 02 2019 *)
PROG
(PARI) {a(n)=polcoeff((1-2*x+2*x^2)*(1+x^2)/(1-x+x*O(x^n))^3, n, x)}
CROSSREFS
KEYWORD
nonn
AUTHOR
Paul D. Hanna, Apr 27 2006
STATUS
approved