cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

Showing 1-5 of 5 results.

A157134 G.f. satisfies: A(x) = Sum_{n>=0} x^(n^2) * A(x)^n.

Original entry on oeis.org

1, 1, 1, 1, 2, 4, 7, 11, 18, 33, 63, 117, 211, 383, 713, 1348, 2547, 4793, 9039, 17165, 32785, 62761, 120243, 230768, 444119, 857015, 1656931, 3207990, 6219994, 12079544, 23496417, 45767352, 89256038, 174269488, 340646238, 666604642
Offset: 0

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Author

Paul D. Hanna, Feb 24 2009

Keywords

Examples

			G.f.: A(x) = 1 + x + x^2 + x^3 + 2*x^4 + 4*x^5 + 7*x^6 + 11*x^7 +...
A(x)^2 = 1 + 2*x + 3*x^2 + 4*x^3 + 7*x^4 + 14*x^5 + 27*x^6 +...
A(x)^3 = 1 + 3*x + 6*x^2 + 10*x^3 + 18*x^4 + 36*x^5 + 73*x^6 +...
A(x)^4 = 1 + 4*x + 10*x^2 + 20*x^3 + 39*x^4 + 80*x^5 + 168*x^6 +...
where
A(x) = 1 + x*A(x) + x^4*A(x)^2 + x^9*A(x)^3 + x^16*A(x)^4 +...
		

Crossrefs

Cf. A107595. [From Paul D. Hanna, Apr 25 2010]

Programs

  • PARI
    {a(n)=local(A=1+x+x*O(x^n));for(i=1,n,(A=sum(m=0,sqrtint(n),x^(m^2)*A^m)));polcoeff(A,n)}

Formula

G.f. satisfies: A(x) = B(x/A(x)) where B(x) = A(x*B(x)) = g.f. of A157135,
where A157135(n) = [x^n] A(x)^(n+1)/(n+1) for n>=0,
and a(n) = [x^n] -1/B(x)^(n-1)/(n-1) for n>1.
From Paul D. Hanna, Apr 25 2010: (Start)
G.f. A(x) satisfies the continued fraction:
A(x) = 1/(1- x*A(x)/(1- (x^3-x)*A(x)/(1- x^5*A(x)/(1- (x^7-x^3)*A(x)/(1- x^9*A(x)/(1- (x^11-x^5)*A(x)/(1- x^13*A(x)/(1- (x^15-x^7)*A(x)/(1- ...)))))))))
due to an identity of a partial elliptic theta function.
(End)
From Paul D. Hanna, May 05 2010: (Start)
Let A = g.f. A(x) at x=q, then A satisfies the q-series:
A = Sum_{n>=0} q^n*A^n*Product_{k=1..n} (1-q^(4k-3)*A)/(1-q^(4k-1)*A).
(End)

Extensions

Typo in data corrected by D. S. McNeil, Aug 17 2010

A157133 G.f. satisfies: A(x) = Sum_{n>=0} x^(n(n+1)/2) * A(x)^n.

Original entry on oeis.org

1, 1, 1, 2, 4, 7, 14, 30, 62, 129, 278, 604, 1313, 2883, 6386, 14203, 31733, 71272, 160725, 363670, 825653, 1880351, 4293985, 9830499, 22558939, 51880565, 119552907, 276012657, 638348123, 1478749229, 3430799333, 7971134523
Offset: 0

Views

Author

Paul D. Hanna, Feb 24 2009

Keywords

Examples

			G.f.: A(x) = 1 + x + x^2 + 2*x^3 + 4*x^4 + 7*x^5 + 14*x^6 + 30*x^7 +...
A(x)^2 = 1 + 2*x + 3*x^2 + 6*x^3 + 13*x^4 + 26*x^5 + 54*x^6 +...
A(x)^3 = 1 + 3*x + 6*x^2 + 13*x^3 + 30*x^4 + 66*x^5 + 145*x^6 +...
A(x)^4 = 1 + 4*x + 10*x^2 + 24*x^3 + 59*x^4 + 140*x^5 + 326*x^6 +...
where
A(x) = 1 + x*A(x) + x^3*A(x)^2 + x^6*A(x)^3 + x^10*A(x)^4 +...
		

Crossrefs

Cf. A121690. [From Paul D. Hanna, Apr 25 2010]

Programs

  • PARI
    {a(n)=local(A=1+x+x*O(x^n));for(i=1,n,(A=sum(m=0,sqrtint(2*n+1),x^(m*(m+1)/2)*A^m)));polcoeff(A,n)}

Formula

Contribution from Paul D. Hanna, Apr 25 2010: (Start)
G.f. A(x) satisfies the continued fraction:
A(x) = 1/(1- x*A(x)/(1- (x^2-x)*A(x)/(1- x^3*A(x)/(1- (x^4-x^2)*A(x)/(1- x^5*A(x)/(1- (x^6-x^3)*A(x)/(1- x^7*A(x)/(1- (x^8-x^4)*A(x)/(1- ...)))))))))
due to an identity of a partial elliptic theta function.
(End)

A157135 G.f. satisfies: A(x) = Sum_{n>=0} x^(n^2) * A(x)^(n^2+n).

Original entry on oeis.org

1, 1, 2, 5, 15, 50, 177, 649, 2437, 9322, 36214, 142546, 567409, 2280246, 9238883, 37699021, 154783906, 638983998, 2650697658, 11043733080, 46192300706, 193892210528, 816486626337, 3448376227978, 14603301098654, 61996178908151
Offset: 0

Views

Author

Paul D. Hanna, Feb 24 2009

Keywords

Examples

			G.f.: A(x) = 1 + x + 2*x^2 + 5*x^3 + 15*x^4 + 50*x^5 + 177*x^6 +...
A(x)^2 = 1 + 2*x + 5*x^2 + 14*x^3 + 44*x^4 + 150*x^5 + 539*x^6 +...
A(x)^6 = 1 + 6*x + 27*x^2 + 110*x^3 + 435*x^4 + 1716*x^5 +...
A(x)^12 = 1 + 12*x + 90*x^2 + 544*x^3 + 2919*x^4 + 14592*x^5 +...
where
A(x) = 1 + x*A(x)^2 + x^4*A(x)^6 + x^9*A(x)^12 + x^16*A(x)^20 +...
		

Crossrefs

Programs

  • PARI
    {a(n)=local(A=1+x+x*O(x^n));for(i=1,n,(A=sum(m=0,sqrtint(n),x^(m^2)*A^(m*(m+1)))));polcoeff(A,n)}

Formula

G.f. satisfies: A(x) = B(x*A(x)) where B(x) = A(x/B(x)) = g.f. of A157134,
where A157134(n) = [x^n] -1/A(x)^(n-1)/(n-1) for n>1,
and a(n) = [x^n] B(x)^(n+1)/(n+1) for n>=0.

A191813 G.f. satisfies: A(x) = Sum_{n>=0} x^(n^2)*A(x)^(n^3).

Original entry on oeis.org

1, 1, 1, 1, 2, 10, 46, 166, 504, 1425, 4256, 14594, 55783, 220903, 873199, 3436817, 13569556, 53929244, 215352055, 861477251, 3446980935, 13792641374, 55203566064, 221112089602, 887538377345, 3580304912835, 14573568107348
Offset: 0

Views

Author

Paul D. Hanna, Jun 17 2011

Keywords

Examples

			G.f.: A(x) = 1 + x + x^2 + x^3 + 2*x^4 + 10*x^5 + 46*x^6 + 166*x^7 +...
where the g.f. satisfies:
A(x) = 1 + x*A(x) + x^4*A(x)^8 + x^9*A(x)^27 + x^16*A(x)^64 + x^25*A(x)^125 + x^36*A(x)^216 +...+ x^(n^2)*A(x)^(n^3) +...
		

Crossrefs

Programs

  • PARI
    {a(n)=local(A=1+x);for(i=1,n,A=1+sum(m=1,n,x^(m^2)*(A+x*O(x^n))^(m^3)));polcoeff(A,n)}

A191814 G.f. satisfies: A(x) = Sum_{n>=0} x^(n^2)*A(x)^(n^4).

Original entry on oeis.org

1, 1, 1, 1, 2, 18, 154, 970, 4862, 20879, 83672, 353281, 1773612, 11060634, 84779040, 772415014, 7726721969, 77774342729, 747754441850, 6734769291340, 56695273838174, 448350981091266, 3357088027977272, 24017325363442968
Offset: 0

Views

Author

Paul D. Hanna, Jun 17 2011

Keywords

Examples

			G.f.: A(x) = 1 + x + x^2 + x^3 + 2*x^4 + 18*x^5 + 154*x^6 + 970*x^7 +...
where the g.f. satisfies:
A(x) = 1 + x*A(x) + x^4*A(x)^16 + x^9*A(x)^81 + x^16*A(x)^256 + x^25*A(x)^625 + x^36*A(x)^1296 +...+ x^(n^2)*A(x)^(n^4) +...
		

Crossrefs

Programs

  • PARI
    {a(n)=local(A=1+x);for(i=1,n,A=1+sum(m=1,n,x^(m^2)*(A+x*O(x^n))^(m^4)));polcoeff(A,n)}
Showing 1-5 of 5 results.