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.

Previous Showing 11-15 of 15 results.

A365035 E.g.f. satisfies A(x) = exp(x * (1 + x/A(x))).

Original entry on oeis.org

1, 1, 3, 1, -11, 61, 301, -6299, 7561, 903673, -9019079, -145636919, 4305630781, 7516191541, -2037845181371, 22442805921901, 944219385367441, -29922880660473359, -288352494154313999, 32071808922904896913, -273044292430852251899
Offset: 0

Views

Author

Seiichi Manyama, Aug 17 2023

Keywords

Crossrefs

Programs

  • PARI
    my(N=30, x='x+O('x^N)); Vec(serlaplace(exp(x+lambertw(x^2*exp(-x)))))

Formula

E.g.f.: exp( x + LambertW(x^2*exp(-x)) ).
a(n) = n! * Sum_{k=1..n} (-n+k+1)^(k-1) * binomial(k,n-k)/k! for n>0.

A365036 E.g.f. satisfies A(x) = exp(x * (1 + x/A(x)^2)).

Original entry on oeis.org

1, 1, 3, -5, -23, 521, -1829, -71021, 1319697, 5905297, -683965709, 8664974891, 311864420473, -13981842414695, 6694007756619, 16448800124183491, -448649039951220959, -13236887251789967071, 1210629233913421852387, -12065049302884271631269
Offset: 0

Views

Author

Seiichi Manyama, Aug 17 2023

Keywords

Crossrefs

Programs

  • PARI
    my(N=20, x='x+O('x^N)); Vec(serlaplace(exp(x+lambertw(2*x^2*exp(-2*x))/2)))

Formula

E.g.f.: exp( x + LambertW(2*x^2*exp(-2*x))/2 ).
a(n) = n! * Sum_{k=0..n} (-2*n+2*k+1)^(k-1) * binomial(k,n-k)/k!.

A365037 E.g.f. satisfies A(x) = exp(x * (1 + x/A(x)^3)).

Original entry on oeis.org

1, 1, 3, -11, -11, 1341, -14339, -168923, 8905065, -85313735, -4604578919, 197455645641, -273728455571, -267002430142187, 9427821270512373, 178475402982086701, -28273343910563670959, 713736314833387866225, 51907546734507018043057
Offset: 0

Views

Author

Seiichi Manyama, Aug 17 2023

Keywords

Crossrefs

Programs

  • PARI
    my(N=20, x='x+O('x^N)); Vec(serlaplace(exp(x+lambertw(3*x^2*exp(-3*x))/3)))

Formula

E.g.f.: exp( x + LambertW(3*x^2*exp(-3*x))/3 ).
a(n) = n! * Sum_{k=0..n} (-3*n+3*k+1)^(k-1) * binomial(k,n-k)/k!.

A228563 E.g.f: A(x) = Sum_{n>=0} (1 + x*A(x)^n)^n * x^n/n!.

Original entry on oeis.org

1, 1, 3, 13, 109, 1241, 18541, 340495, 7475721, 191215729, 5590994041, 184086712151, 6745657327069, 272484296020249, 12037353264295269, 577681783128081871, 29946086856245571601, 1668620115204908947937, 99516760157428436346481, 6329149392153729480812839
Offset: 0

Views

Author

Paul D. Hanna, Aug 25 2013

Keywords

Crossrefs

Cf. A143768.

Programs

  • PARI
    {a(n)=local(A=1+x);for(i=1,n,A=sum(k=0,n,(1+x*A^k +x*O(x^n))^k*x^k/k!));n!*polcoeff(A,n)}
    for(n=0,30,print1(a(n),", "))

Formula

E.g.f.: A(x) = 1 + x + 3*x^2/2! + 13*x^3/3! + 109*x^4/4! + 1241*x^5/5! +...
where
A(x) = 1 + (1+x*A(x))*x + (1+x*A(x)^2)^2*x^2/2! + (1+x*A(x)^3)^3*x^3/3! + (1+x*A(x)^4)^4*x^4/4! + (1+x*A(x)^5)^5*x^5/5! +...

A372182 E.g.f. A(x) satisfies A(x) = exp( x * A(x)^5 * (1 + x * A(x)^2) ).

Original entry on oeis.org

1, 1, 13, 334, 13329, 724316, 49939411, 4177202562, 411049275265, 46530896718520, 5957142774561531, 851104158600401366, 134246582420467536289, 23171656877102178017028, 4344395473350526080895843, 879206880413471231912831626, 191028062860784640128743389441
Offset: 0

Views

Author

Seiichi Manyama, Apr 21 2024

Keywords

Crossrefs

Programs

  • PARI
    a(n, r=1, s=1, t=5, u=2) = r*n!*sum(k=0, n, (t*k+u*(n-k)+r)^(k-1)*binomial(s*k, n-k)/k!);

Formula

If e.g.f. satisfies A(x) = exp( r*x*A(x)^(t/r) * (1 + x*A(x)^(u/r))^s ), then a(n) = r * n! * Sum_{k=0..n} (t*k+u*(n-k)+r)^(k-1) * binomial(s*k,n-k)/k!.
Previous Showing 11-15 of 15 results.