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 1-4 of 4 results.

A198944 G.f.: A(x) = exp( Sum_{n>=1} [Sum_{k=0..n} C(n,k)^3 * x^k*A(x)^k] * x^n/n ).

Original entry on oeis.org

1, 1, 2, 7, 23, 78, 291, 1126, 4436, 17910, 73773, 308188, 1303402, 5573133, 24050795, 104620985, 458324429, 2020417339, 8956142180, 39899217350, 178549985024, 802275736073, 3618237414959, 16373514195570, 74325340129430, 338356926399193, 1544406450870590
Offset: 0

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Author

Paul D. Hanna, Oct 31 2011

Keywords

Comments

Compare to a g.f. G(x) of A036765 (rooted trees with a degree constraint):
G(x) = exp( Sum_{n>=1} [Sum_{k=0..n} C(n,k)^2 * x^k*G(x)^k] * x^n/n ).

Examples

			G.f.: A(x) = 1 + x + 2*x^2 + 7*x^3 + 23*x^4 + 78*x^5 + 291*x^6 +...
where
log(A(x)) = (1 + x*A(x))*x + (1 + 2^3*x*A(x) + x^2*A(x)^2)*x^2/2 +
(1 + 3^3*x*A(x) + 3^3*x^2*A(x)^2 + x^3*A(x)^3)*x^3/3 +
(1 + 4^3*x*A(x) + 6^3*x^2*A(x)^2 + 4^3*x^3*A(x)^3 + x^4*A(x)^4)*x^4/4 +
(1 + 5^3*x*A(x) + 10^3*x^2*A(x)^2 + 10^3*x^3*A(x)^3 + 5^3*x^4*A(x)^4 + x^5*A(x)^5)*x^5/5 +...
more explicitly,
log(A(x)) = x + 3*x^2/2 + 16*x^3/3 + 63*x^4/4 + 251*x^5/5 + 1110*x^6/6 +...
		

Crossrefs

Programs

  • PARI
    {a(n)=local(A=1+x); for(i=1, n, A=exp(sum(m=1, n, sum(j=0, m, binomial(m, j)^3*(x*A+x*O(x^n))^j)*x^m/m))); polcoeff(A, n, x)}

A200212 G.f. satisfies: A(x) = exp( Sum_{n>=1} [Sum_{k=0..n} C(n,k)^3 * x^k*A(x)^(n-k)] * x^n/n ).

Original entry on oeis.org

1, 1, 3, 11, 42, 174, 763, 3457, 16075, 76351, 368767, 1805682, 8943948, 44736096, 225646033, 1146461185, 5862224756, 30144922281, 155791900727, 808773877919, 4215675455503, 22054576750972, 115765182718467, 609508331610920, 3218059655553030, 17034314889643633
Offset: 0

Views

Author

Paul D. Hanna, Nov 14 2011

Keywords

Examples

			G.f.: A(x) = 1 + x + 3*x^2 + 11*x^3 + 42*x^4 + 174*x^5 + 763*x^6 +...
where the logarithm of the g.f. A = A(x) equals the series:
log(A(x)) = (A + x)*x + (A^2 + 2^3*x*A + x^2)*x^2/2 +
(A^3 + 3^3*x*A^2 + 3^3*x^2*A + x^3)*x^3/3 +
(A^4 + 4^3*x*A^3 + 6^3*x^2*A^2 + 4^3*x^3*A + x^4)*x^4/4 +
(A^5 + 5^3*x*A^4 + 10^3*x^2*A^3 + 10^3*x^3*A^2 + 5^3*x^4*A + x^5)*x^5/5 +
(A^6 + 6^3*x*A^5 + 15^3*x^2*A^4 + 20^3*x^3*A^3 + 15^3*x^4*A^2 + 6^3*x^5*A + x^6)*x^6/6 +...
more explicitly,
log(A(x)) = x + 5*x^2/2 + 25*x^3/3 + 117*x^4/4 + 581*x^5/5 + 2987*x^6/6 + 15499*x^7/7 + 81213*x^8/8 +...
		

Crossrefs

Programs

  • PARI
    {a(n)=local(A=1+x); for(i=1, n, A=exp(sum(m=1, n, sum(j=0, m, binomial(m, j)^3*x^j/A^j)*(x*A+x*O(x^n))^m/m))); polcoeff(A, n, x)}

A192204 G.f.: A(x) = exp( Sum_{n>=1} (Sum_{k=0..n} C(n,k)^4*A(x)^k) * x^n/n ).

Original entry on oeis.org

1, 2, 13, 109, 1099, 12283, 147620, 1869346, 24633344, 334916467, 4669887745, 66481991644, 963096090267, 14160279233964, 210870471771803, 3175275874056722, 48281516978747396, 740504452581897112, 11444972742343813815
Offset: 0

Views

Author

Paul D. Hanna, Jun 25 2011

Keywords

Examples

			G.f.: A(x) = 1 + 2*x + 13*x^2 + 109*x^3 + 1099*x^4 + 12283*x^5 +...
which satisfies:
log(A(x)) = (1 + A(x))*x + (1 + 16*A(x) + A(x)^2)*x^2/2 + (1 + 81*A(x) + 81*A(x)^2 + A(x)^3)*x^3/3 + (1 + 256*A(x) + 1296*A(x)^2 + 256*A(x)^3 + A(x)^4)*x^4/4 +...
		

Crossrefs

Cf. variants: A007863, A192131.

Programs

  • PARI
    {a(n)=local(A=1+x); for(i=1, n, A=exp(sum(m=1, n, sum(j=0, m, binomial(m, j)^4*(A+x*O(x^n))^j)*x^m/m))); polcoeff(A, n, x)}

A200215 G.f. satisfies: A(x) = exp( Sum_{n>=1} (Sum_{k=0..n} C(n,k)^3 * x^k*A(x)^k) * x^n*A(x)^n/n ).

Original entry on oeis.org

1, 1, 3, 13, 61, 306, 1623, 8937, 50565, 292283, 1718827, 10250916, 61854848, 376949934, 2316738789, 14343701657, 89379109846, 560108223900, 3527723269978, 22318890516413, 141778326349191, 903936594232782, 5782447430948438, 37102633354583532, 238729798670985104
Offset: 0

Views

Author

Paul D. Hanna, Nov 14 2011

Keywords

Examples

			G.f.: A(x) = 1 + x + 3*x^2 + 13*x^3 + 61*x^4 + 306*x^5 + 1623*x^6 +...
where the logarithm of the g.f. A = A(x) equals the series:
log(A(x)) = (1 + x*A)*x*A + (1 + 2^3*x*A + x^2*A^2)*x^2*A^2/2 +
(1 + 3^3*x*A + 3^3*x^2*A^2 + x^3*A^3)*x^3*A^3/3 +
(1 + 4^3*x*A + 6^3*x^2*A^2 + 4^3*x^3*A^3 + x^4*A^4)*x^4*A^4/4 +
(1 + 5^3*x*A + 10^3*x^2*A^2 + 10^3*x^3*A^3 + 5^3*x^4*A^4 + x^5*A^5)*x^5*A^5/5 +
(1 + 6^3*x*A + 15^3*x^2*A^2 + 20^3*x^3*A^3 + 15^3*x^4*A^4 + 6^3*x^5*A^5 + x^6*A^6)*x^6*A^6/6 +...
more explicitly,
log(A(x)) = x + 5*x^2/2 + 31*x^3/3 + 185*x^4/4 + 1126*x^5/5 + 7043*x^6/6 + 44689*x^7/7 + 286241*x^8/8 +...
		

Crossrefs

Programs

  • PARI
    {a(n)=local(A=1+x); for(i=1, n, A=exp(sum(m=1, n, sum(j=0, m, binomial(m, j)^3*x^j*A^j)*(x*A+x*O(x^n))^m/m))); polcoeff(A, n, x)}
Showing 1-4 of 4 results.