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 1-3 of 3 results.

A303058 G.f. A(x) satisfies: A(x) = Sum_{n>=0} (1+x)^(n^2) * x^n / A(x)^n.

Original entry on oeis.org

1, 1, 1, 2, 5, 16, 61, 259, 1228, 6284, 34564, 201978, 1246652, 8084728, 54862377, 388266809, 2857708840, 21822753453, 172550972216, 1410144139982, 11892084248959, 103343300813517, 924223611649636, 8496346816801059, 80201063980292729, 776585923239589681, 7706568335863727817, 78311132374535936605
Offset: 0

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Author

Paul D. Hanna, Apr 20 2018

Keywords

Examples

			G.f.: A(x) = 1 + x + x^2 + 2*x^3 + 5*x^4 + 16*x^5 + 61*x^6 + 259*x^7 + 1228*x^8 + 6284*x^9 + 34564*x^10 + 201978*x^11 + 1246652*x^12 + ...
such that
A(x) = 1 + (1+x)*x/A(x) + (1+x)^4*x^2/A(x)^2 + (1+x)^9*x^3/A(x)^3 + (1+x)^16*x^4/A(x)^4 + (1+x)^25*x^5/A(x)^5 + (1+x)^36*x^6/A(x)^6 + ...
		

Crossrefs

Programs

  • PARI
    {a(n) = my(A=[1]); for(i=1,n, A = concat(A,0); A[#A] = Vec(sum(n=0,#A, ((1+x)^n +x*O(x^#A))^n * x^n/Ser(A)^n ) )[#A] );A[n+1]}
    for(n=0,30,print1(a(n),", "))

Formula

G.f.: A(x) = 1/(1 - q*x/(A(x) - q*(q^2-1)*x/(1 - q^5*x/(A(x) - q^3*(q^4-1)*x/(1 - q^9*x/(A(x) - q^5*(q^6-1)*x/(1 - q^13*x/(A(x) - q^7*(q^8-1)*x/(1 - ...))))))))), where q = (1+x), a continued fraction due to a partial elliptic theta function identity.
G.f.: A(x) = Sum_{n>=0} x^n/A(x)^n * (1+x)^n * Product_{k=1..n} (A(x) - x*(1+x)^(4*k-3)) / (A(x) - x*(1+x)^(4*k-1)), due to a q-series identity.

A301927 G.f. A(x) satisfies: x = Sum_{n>=1} x^n / ( (1-x)^(n^2) * A(x)^n ).

Original entry on oeis.org

1, 2, 4, 9, 24, 77, 294, 1296, 6403, 34644, 201932, 1253513, 8219110, 56578239, 406990651, 3048202700, 23700070773, 190830842843, 1588016365186, 13633603416558, 120574656241999, 1097006289005674, 10255338612462641, 98403208150304070, 968186766428157206, 9759036265967791137, 100690787844977985900, 1062601625749170026894, 11461320511629994319890
Offset: 0

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Author

Paul D. Hanna, May 06 2018

Keywords

Examples

			G.f.: A(x) = 1 + 2*x + 4*x^2 + 9*x^3 + 24*x^4 + 77*x^5 + 294*x^6 + 1296*x^7 + 6403*x^8 + 34644*x^9 + 201932*x^10 + 1253513*x^11 + 8219110*x^12 + ...
such that
x = x/((1-x)*A(x)) + x^2/((1-x)^4*A(x)^2) + x^3/((1-x)^9*A(x)^3) + x^4/((1-x)^16*A(x)^4) + x^5/((1-x)^25*A(x)^5) + x^6/((1-x)^36*A(x)^6) + x^7/((1-x)^49*A(x)^7) + x^8/((1-x)^64*A(x)^8) + ...
		

Crossrefs

Cf. A301929.

Programs

  • PARI
    {a(n) = my(A=[1]); for(i=1, n, A = concat(A, 0); A[#A] = Vec(sum(n=0, #A, x^n/(((1-x)^n +x*O(x^#A))^n * Ser(A)^n) ) )[#A+1] ); A[n+1]}
    for(n=0, 30, print1(a(n), ", "))

Formula

G.f.: x = Sum_{n>=1} x^n/A(x)^n * (1-x)^n * Product_{k=1..n} (x - (1-x)^(4*k-3)*A(x)) / (x - (1-x)^(4*k-1)*A(x)), due to a q-series identity.
G.f.: 1+x = 1/(1 - q*x/(A(x) - q*(q^2-1)*x/(1 - q^5*x/(A(x) - q^3*(q^4-1)*x/(1 - q^9*x/(A(x) - q^5*(q^6-1)*x/(1 - q^13*x/(A(x) - q^7*(q^8-1)*x/(1 - ...))))))))), where q = 1/(1-x), a continued fraction due to a partial elliptic theta function identity.

A320954 G.f. A(x) satisfies: 1/(1-x) = Sum_{n>=0} (1+x)^(n^2) * x^n / A(x)^n.

Original entry on oeis.org

1, 1, 2, 5, 14, 50, 200, 919, 4633, 25361, 148606, 923394, 6043996, 41447150, 296571213, 2206965193, 17034374165, 136066491764, 1122656493744, 9552206133005, 83695193972045, 754199756930791, 6981787930209535, 66327351641879318, 646031757787129761, 6445726513363688990, 65825739028009602120, 687540665329016479660
Offset: 0

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Author

Paul D. Hanna, Oct 25 2018

Keywords

Examples

			G.f.: A(x) = 1 + x + 2*x^2 + 5*x^3 + 14*x^4 + 50*x^5 + 200*x^6 + 919*x^7 + 4633*x^8 + 25361*x^9 + 148606*x^10 + 923394*x^11 + 6043996*x^12 + ...
such that
1/(1-x) = 1 + (1+x)*x/A(x) + (1+x)^4*x^2/A(x)^2 + (1+x)^9*x^3/A(x)^3 + (1+x)^16*x^4/A(x)^4 + (1+x)^25*x^5/A(x)^5 + (1+x)^36*x^6/A(x)^6 + ...
		

Crossrefs

Programs

  • PARI
    {a(n) = my(A=[1]); for(i=1, n, A = concat(A, 0); A[#A] = -1 + Vec(sum(n=0, #A, ((1+x)^n +x*O(x^#A))^n * x^n/Ser(A)^n ) )[#A+1] ); A[n+1]}
    for(n=0, 30, print1(a(n), ", "))

Formula

Given g.f. A(x) then
(1) 1/(1-x) = 1/(1 - q*x/(A(x) - q*(q^2-1)*x/(1 - q^5*x/(A(x) - q^3*(q^4-1)*x/(1 - q^9*x/(A(x) - q^5*(q^6-1)*x/(1 - q^13*x/(A(x) - q^7*(q^8-1)*x/(1 - ...))))))))), where q = (1+x), a continued fraction due to a partial elliptic theta function identity.
(2) 1/(1-x) = Sum_{n>=0} x^n/A(x)^n * (1+x)^n * Product_{k=1..n} (A(x) - x*(1+x)^(4*k-3)) / (A(x) - x*(1+x)^(4*k-1)), due to a q-series identity.
Showing 1-3 of 3 results.