A184577 G.f.: A(x) = 1+x*(1+x*(1+x*(...(1+x*(...)^(5^n) )...)^125)^25)^5.

1, 1, 5, 135, 17635, 11196380, 35146865626, 549810415675025, 42966178319025765725, 16784792206658535573353275, 32783305434744311217446987595100, 320150590803319511079060107920058643150

Offset

0,3

Comments

Limit a(n)/5^[n(n-1)/2] = 1.153465224918418179626705381295781...

Links

Table of n, a(n) for n=0..11.

Example

 G.f.: A(x) = 1 + x + 5*x^2 + 135*x^3 + 17635*x^4 + 11196380*x^5 +...
Related functions are defined by:
A(x) = 1 + x*B(x)^5;
B(x) = 1 + x*C(x)^25;
C(x) = 1 + x*D(x)^125;
D(x) = 1 + x*E(x)^625;
E(x) = 1 + x*F(x)^3125; ...
where the coefficients in the above functions begin:
B=[1,1,25,3425,2224175,7020109525,109933742396880,8592795153472287100,...];
C=[1,1,125,85875,278520875,4390379300750,343605429779453150,...];
D=[1,1,625,2148125,34827604375,2744338779394375,1073806035818802734500,...];
E=[1,1,3125,53709375,4353763021875,1715255710695800000,...];
F=[1,1,15625,1342765625,544228190109375,1072040316107238765625,...].

Prog

 (PARI) {a(n)=local(A=1+x+x*O(x^n)); for(j=0, n-1, A=1+x*A^(5^(n-j))); polcoeff(A, n)}

Crossrefs

Cf. A120959, A184575, A184576.

Sequence in context: A132508 A215218 A159355 * A229772 A082212 A208867

Adjacent sequences: A184574 A184575 A184576 * A184578 A184579 A184580

Keyword

nonn

Author

Paul D. Hanna, Jan 17 2011

Status

approved