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 1-8 of 8 results.

A113670 Self-convolution 4th power equals A113664, where a(n) = n*A113664(n-1) for n>=1, with a(0)=1.

Original entry on oeis.org

1, 1, 8, 114, 2224, 53725, 1528200, 49703108, 1813503712, 73247619060, 3242579748000, 156107189374202, 8121266448765936, 454110696002834806, 27165980379205109232, 1731608155057922555400, 117183510733473232477120
Offset: 0

Views

Author

Paul D. Hanna, Nov 04 2005

Keywords

Crossrefs

Programs

  • PARI
    {a(n)=local(A=1+x*O(x^n));for(i=1,n, A=1+x*deriv(x*A^4));polcoeff(A,n,x)}

Formula

G.f. A(x) satisfies:
(1) A(x) = 1 + x*d/dx[x*A(x)^4],
(2) [x^n] exp( x*A(x)^4 ) * (n + 1 - A(x)) = 0 for n > 0,
(3) [x^n] exp( n * x*A(x)^4 ) * (2 - A(x)) = 0 for n > 0. - Paul D. Hanna, May 27 2018

A113663 Self-convolution cube of A113669, where a(n) = A113669(n+1)/(n+1).

Original entry on oeis.org

1, 3, 21, 226, 3216, 56229, 1158249, 27367560, 728245038, 21531918486, 700096811670, 24826071871890, 953594302010230, 39446976470619801, 1748616265593936681, 82701936091459565976, 4157268410857737364182
Offset: 0

Views

Author

Paul D. Hanna, Nov 04 2005

Keywords

Crossrefs

Programs

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

Formula

G.f. satisfies: A(x) = (1 + x*d/dx[x*A(x)] )^3.
a(n) ~ c * 3^n * n! * n^(2/3), where c = 0.7528584991179137287053869... - Vaclav Kotesovec, Oct 23 2020

A113665 Self-convolution 5th power of A113671, where a(n) = A113671(n+1)/(n+1).

Original entry on oeis.org

1, 5, 60, 1110, 27105, 811026, 28511130, 1146762120, 51826136580, 2597311722545, 142897603735880, 8561763675801900, 554962861232408910, 38698651781787343980, 2889100726488051970230, 229948324353525499175160
Offset: 0

Views

Author

Paul D. Hanna, Nov 04 2005

Keywords

Crossrefs

Programs

  • PARI
    {a(n)=local(A=1+x*O(x^n));for(i=1,n, A=(1+x*deriv(x*A))^5);polcoeff(A,n,x)}

Formula

G.f. satisfies: A(x) = (1 + x*d/dx[x*A(x)] )^5.
a(n) ~ c * 5^n * n! * n^(4/5), where c = 0.688632085705020709346557... - Vaclav Kotesovec, Oct 23 2020

A113666 Self-convolution 6th power of A113672, where a(n) = A113672(n+1)/(n+1).

Original entry on oeis.org

1, 6, 87, 1946, 57429, 2075376, 88058362, 4272270786, 232769956974, 14056832143770, 931523802358452, 67202173618455120, 5243275012537211083, 439986956480236610424, 39519795153012732250740
Offset: 0

Views

Author

Paul D. Hanna, Nov 04 2005

Keywords

Crossrefs

Programs

  • PARI
    {a(n)=local(A=1+x*O(x^n));for(i=1,n, A=(1+x*deriv(x*A))^6);polcoeff(A,n,x)}

Formula

G.f. satisfies: A(x) = (1 + x*d/dx[x*A(x)] )^6.
a(n) ~ c * 6^n * n! * n^(5/6), where c = 0.67248889832227393928944... - Vaclav Kotesovec, Oct 23 2020

A113667 Self-convolution 7th power of A113673, where a(n) = A113673(n+1)/(n+1).

Original entry on oeis.org

1, 7, 119, 3122, 108031, 4575543, 227428166, 12920344256, 823981508700, 58224680389435, 4513525625433076, 380801193456921958, 34738963053424196609, 3407790141561016562022, 357764735284328750251272
Offset: 0

Views

Author

Paul D. Hanna, Nov 04 2005

Keywords

Crossrefs

Programs

  • PARI
    {a(n)=local(A=1+x*O(x^n));for(i=1,n, A=(1+x*deriv(x*A))^7);polcoeff(A,n,x)}

Formula

G.f. satisfies: A(x) = (1 + x*d/dx[x*A(x)] )^7.
a(n) ~ c * 7^n * n! * n^(6/7), where c = 0.6609663441165155995412... - Vaclav Kotesovec, Oct 23 2020

A113668 Self-convolution 8th power of A113674, where a(n) = A113674(n+1)/(n+1).

Original entry on oeis.org

1, 8, 156, 4696, 186406, 9053640, 515875660, 33585910968, 2453913830097, 198609146859416, 17630476159933080, 1703025192274201272, 177846105338917975896, 19968484152350242447288
Offset: 0

Views

Author

Paul D. Hanna, Nov 04 2005

Keywords

Comments

From Vaclav Kotesovec, Oct 23 2020: (Start)
In general, for k>=1, if g.f. satisfies: A(x) = (1 + x*d/dx[x*A(x)] )^k, then a(n) ~ c(k) * k^n * n! * n^((k-1)/k), where c(k) is a constant (dependent only on k).
c(k) tends to A238223*exp(1) = 0.592451670452494179138706... if k tends to infinity.
(End)

Crossrefs

Programs

  • PARI
    {a(n)=local(A=1+x*O(x^n));for(i=1,n, A=(1+x*deriv(x*A))^8);polcoeff(A,n,x)}

Formula

G.f. satisfies: A(x) = (1 + x*d/dx[x*A(x)] )^8.
a(n) ~ c * 8^n * n! * n^(7/8), where c = 0.6523348263871879460325... - Vaclav Kotesovec, Oct 23 2020

A113662 G.f. satisfies: A(x) = (1 + x*(d/dx x*A(x)) )^2.

Original entry on oeis.org

1, 2, 9, 62, 566, 6372, 84837, 1300214, 22511322, 434226300, 9231983850, 214481625516, 5406323440492, 146963638311880, 4286068830850797, 133501081493969574, 4423404073559930162, 155359770700317171084
Offset: 0

Views

Author

Paul D. Hanna, Nov 04 2005

Keywords

Comments

Self-convolution of A000699 (after ignoring the initial term), [previous name].

Examples

			G.f. A(x) = 1 + 2*x + 9*x^2 + 62*x^3 + 566*x^4 + 6372*x^5 + 84837*x^6 + 1300214*x^7 + ...
		

Crossrefs

Programs

  • PARI
    {a(n)=local(A=1+x*O(x^n));for(i=1,n, A=(1+x*deriv(x*A))^2);polcoeff(A,n,x)}
    
  • PARI
    A000699_seq(N) = {
      my(a = vector(N)); a[1] = 1;
      for (n=2, N, a[n] = sum(k=1, n-1, (2*k-1)*a[k]*a[n-k])); a;
    };
    Vec(sqr(Ser(A000699_seq(N))))  \\ Gheorghe Coserea, Jan 23 2017

Formula

G.f. satisfies: A(x) = (1 + x*(d/dx x*A(x)) )^2.
a(n) ~ 2^(n + 5/2) * n^(n+1) / exp(n+1). - Vaclav Kotesovec, Oct 23 2020

Extensions

Name replaced with an existing formula by Paul D. Hanna, Sep 16 2024

A338377 G.f. satisfies: A(x) = (1 + x * d/dx(x*A(x)) )^n.

Original entry on oeis.org

1, 1, 9, 226, 10745, 811026, 88058362, 12920344256, 2453913830097, 584608650175630, 170543970449421371, 59769169004510011674, 24775053368568412720967, 11989194513429991057937296, 6698670769128767044654361520, 4280089524780608663200103685056, 3101341801862271814724389007080481
Offset: 0

Views

Author

Vaclav Kotesovec, Oct 23 2020

Keywords

Examples

			a(2) = A113662(2) = 9
a(3) = A113663(3) = 226
a(4) = A113664(4) = 10745
a(5) = A113665(5) = 811026
a(6) = A113666(6) = 88058362
a(7) = A113667(7) = 12920344256
a(8) = A113668(8) = 2453913830097
		

Crossrefs

Programs

  • PARI
    {a(n)=local(A=1+x*O(x^n)); for(i=1, n, A=(1+x*deriv(x*A))^n); polcoeff(A, n, x)}
    for(n=0, 20, print1(a(n), ", "))

Formula

G.f. satisfies: A(x) = (1 + x * A(x) + x^2 * A'(x) )^n.
a(n) ~ A238223 * exp(1) * n! * n^(n + 1 - 1/n).
a(n) ~ A238223 * exp(1) * n^(n+1) * n! * (1 - log(n)/n).
Showing 1-8 of 8 results.