A292119 O.g.f. equals the square of the e.g.f. of A291561.

1, 10, 130, 2100, 40950, 943740, 25269300, 774635400, 26836251750, 1038607069500, 44448725821500, 2084869401615000, 106355178306877500, 5861473946222895000, 346999395775257225000, 21956626245257906202000, 1478562610889805715023750, 105561794005139231136877500, 7963731010308915234880987500, 632966979266333111428303275000, 52862553418201438508049805852500

Offset: 2

Author

Paul D. Hanna, Sep 18 2017

Keywords

• nonn

Comments

A291561 is a diagonal in triangle A291560: a(n) = -A291560(n+1, n) for n >= 1; the e.g.f. of triangle A291560 equals arcsin( k*sin(x) ).

Examples

			O.g.f.: A(x) = x^2 + 10*x^3 + 130*x^4 + 2100*x^5 + 40950*x^6 + 943740*x^7 + 25269300*x^8 + 774635400*x^9 + 26836251750*x^10 + 1038607069500*x^11 + 44448725821500*x^12 + 2084869401615000*x^13 + 106355178306877500*x^14 + 5861473946222895000*x^15 + 346999395775257225000*x^16 + 21956626245257906202000*x^17 + 1478562610889805715023750*x^18 + ...
such that the square root of the g.f. equals the e.g.f. of A291561, which begins:
A(x)^(1/2) = x + 10*x^2/2! + 315*x^3/3! + 18900*x^4/4! + 1819125*x^5/5! + 255405150*x^6/6! + 49165491375*x^7/7! + 12417798393000*x^8/8! + 3981456609755625*x^9/9! + 1579311121869731250*x^10/10! + ... + A291561(n)*x^n/n! + ...
		

Crossrefs

Cf. A291561, A291560.

Programs

PARI

{A291560(n, r) = (2*n-1)! * polcoeff( polcoeff( asin( k*sin(x + O(x^(2*n)))), 2*n-1, x), 2*r-1, k)}
{a(n) = polcoeff( sum(m=1,n,-A291560(m+1, m) * x^m / m! +x*O(x^n) )^2, n)}
for(n=2, 25, print1(a(n), ", "))