OFFSET
0,2
LINKS
G. C. Greubel, Rows n = 0..25 of the triangle, flattened
FORMULA
T(n, k) = [x^k](p(x, n, q)) where p(x,n,q) = Product_{j=1..n} (x + q^j) + Product_{j=1..n} (x*q^j + 1), p(x, 0, q) = 1, and q = 2.
EXAMPLE
Triangle begins as:
1;
3, 3;
9, 12, 9;
65, 70, 70, 65;
1025, 990, 560, 990, 1025;
32769, 31806, 11160, 11160, 31806, 32769;
2097153, 2064510, 671832, 178560, 671832, 2064510, 2097153;
MATHEMATICA
p[x_, n_, q_]:= If[n==0, 1, Product[x+q^j, {j, n}] + Product[x*q^j +1, {j, n}]];
T[n_, k_, q_]:= SeriesCoefficient[p[x, n, q], {x, 0, k}];
Table[T[n, k, 2], {n, 0, 10}, {k, 0, n}]//Flatten (* modified by G. C. Greubel, Apr 26 2021 *)
PROG
(Magma)
R<x>:=PowerSeriesRing(Integers(), 50);
p:= func< x, n, q | n eq 0 select 1 else (&*[x+q^j: j in [1..n]]) + (&*[1+q^j*x: j in [1..n]]) >;
T:= func< n, q | Coefficients(R!( p(x, n, q) )) >;
[T(n, 2): n in [0..10]]; // G. C. Greubel, Apr 26 2021
CROSSREFS
KEYWORD
AUTHOR
Roger L. Bagula, Feb 08 2010
EXTENSIONS
Edited by G. C. Greubel, Apr 26 2021
STATUS
approved