OFFSET
0,2
COMMENTS
The rows are generated by iterating the operator E^2*Delta, where E is the forward shift operator, E(f(m)) = f(m + 1), and Delta = E - 1 is the forward difference operator. Equivalently, E^2*Delta = E^2*(E - 1) = E^3 - E^2.
FORMULA
a(n) = Sum_{j=0..n} (-1)^(n - j)*binomial(n, j)*binomial(2*(2*n + j), 2*n + j).
a(n) = (1/Pi)*Integral_{x = 0..4} x^(2*n)*(x - 1)^n/sqrt(x*(4 - x)) dx.
EXAMPLE
Array begins:
n = 0: 1 2 6 20 70 252 924
n = 1: 14 50 182 672 2508 9438
n = 2: 490 1826 6832 25740 97724
n = 3: 19382 73484 280314 1076288
n = 4: 809354 3108624 12022020
CROSSREFS
KEYWORD
nonn
AUTHOR
Dalton Heilig, May 28 2026
STATUS
approved
