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.

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A290575 Apéry-like numbers Sum_{k=0..n} (C(n,k) * C(2*k,n))^2.

Original entry on oeis.org

1, 4, 40, 544, 8536, 145504, 2618176, 48943360, 941244376, 18502137184, 370091343040, 7508629231360, 154145664817600, 3196100636757760, 66834662101834240, 1407913577733228544, 29849617614785770456, 636440695668355742560, 13638210075999240396736, 293565508750164008207104, 6344596821114216520841536
Offset: 0

Views

Author

Hugo Pfoertner, Aug 06 2017

Keywords

Comments

Sequence epsilon in Almkvist, Straten, Zudilin article.

Crossrefs

The Apéry-like numbers [or Apéry-like sequences, Apery-like numbers, Apery-like sequences] include A000172, A000984, A002893, A002895, A005258, A005259, A005260, A006077, A036917, A063007, A081085, A093388, A125143 (apart from signs), A143003, A143007, A143413, A143414, A143415, A143583, A183204, A214262, A219692, A226535, A227216, A227454, A229111 (apart from signs), A260667, A260832, A262177, A264541, A264542, A279619, A290575, A290576. (The term "Apery-like" is not well-defined.)
For primes that do not divide the terms of the sequences A000172, A005258, A002893, A081085, A006077, A093388, A125143, A229111, A002895, A290575, A290576, A005259 see A260793, A291275-A291284 and A133370 respectively.

Programs

  • Mathematica
    Table[Sum[(Binomial[n, k]*Binomial[2*k, n])^2, {k, 0, n}], {n, 0, 25}] (* G. C. Greubel, Oct 23 2017 *)
    a[n_] := Binomial[2 n, n]^2 HypergeometricPFQ[{1/2 - n/2, 1/2 - n/2, -n/2, -n/2}, {1, 1/2 - n, 1/2 - n}, 1];
    Table[a[n], {n, 0, 20}] (* Peter Luschny, Apr 10 2022 *)
  • PARI
    C=binomial; a(n) = sum (k=0, n, C(n,k)^2 * C(k+k,n)^2);

Formula

a(-1)=0, a(0)=1, a(n+1) = ((2*n+1)*(12*n^2+12*n+4)*a(n)-16*n^3*a(n-1))/(n+1)^3.
a(n) = Sum_{k=ceiling(n/2)..n} binomial(n,k)^2*binomial(2*k,n)^2. [Gorodetsky] - Michel Marcus, Feb 25 2021
a(n) ~ 2^(2*n - 3/4) * (1 + sqrt(2))^(2*n+1) / (Pi*n)^(3/2). - Vaclav Kotesovec, Jul 10 2021
From Peter Bala, Apr 10 2022: (Start)
The g.f. is the diagonal of the rational function 1/(1 - (x + y + z + t) + 2*(x*y*z + x*y*t + x*z*t + y*z*t) + 4*x*y*z*t) (Straub and Zudilin)
The g.f. appears to be the diagonal of the rational function 1/(1 - x - y + z - t - 2*(x*z + y*z + z*t) + 4*(x*y*t + x*z*t) + 8*x*y*z*t).
If true, then a(n) = [(x*y*z)^n] ( (x + y + z + 1)*(x + y + z - 1)*(x + y - z - 1)*(x - y - z + 1) )^n . (End)
a(n) = binomial(2*n, n)^2 * hypergeom([1/2-n/2, 1/2-n/2, -n/2, -n/2], [1, 1/2-n, 1/2-n], 1). - Peter Luschny, Apr 10 2022
G.f.: hypergeom([1/8, 3/8],[1], 256*x^2 / (1 - 4*x)^4)^2 / (1 - 4*x). - Mark van Hoeij, Nov 12 2022
a(n) = [(w*x*y*z)^n] ((w+z)*(x+z)*(y+z)*(w+x+y+z))^n = Sum_{0 <= j <= i <= n} binomial(n,i)^2*binomial(i,j)^2*binomial(n+j,i). - Jeremy Tan, Mar 28 2024

A290576 Apéry-like numbers Sum_{k=0..n} Sum_{l=0..n} (C(n,k)^2*C(n,l)*C(k,l)*C(k+l,n)).

Original entry on oeis.org

1, 3, 27, 309, 4059, 57753, 866349, 13492251, 216077787, 3536145057, 58875891777, 994150929951, 16984143140589, 293036113226223, 5098773125244483, 89368239352074309, 1576424378494272987, 27964450505226314673, 498550055166916502121
Offset: 0

Views

Author

Hugo Pfoertner, Aug 06 2017

Keywords

Comments

Sequence zeta (formula 4.12) in Almkvist, Straten, Zudilin article.

Crossrefs

The Apéry-like numbers [or Apéry-like sequences, Apery-like numbers, Apery-like sequences] include A000172, A000984, A002893, A002895, A005258, A005259, A005260, A006077, A036917, A063007, A081085, A093388, A125143 (apart from signs), A143003, A143007, A143413, A143414, A143415, A143583, A183204, A214262, A219692, A226535, A227216, A227454, A229111 (apart from signs), A260667, A260832, A262177, A264541, A264542, A279619, A290575, A290576. (The term "Apery-like" is not well-defined.)
For primes that do not divide the terms of the sequences A000172, A005258, A002893, A081085, A006077, A093388, A125143, A229111, A002895, A290575, A290576, A005259 see A260793, A291275-A291284 and A133370 respectively.

Programs

  • Maple
    f:= gfun:-rectoproc({a(0)=1, a(1)=3, a(n+1) = ( (2*n+1)*(9*n^2+9*n+3)*a(n) + 27*n^3*a(n-1) ) / (n+1)^3}, a(n), remember):
    map(f, [$0..30]); # Robert Israel, Aug 07 2017
  • Mathematica
    Table[Sum[Sum[(Binomial[n, k]^2*Binomial[n, j] Binomial[k, j] Binomial[k + j, n]), {j, 0, n} ], {k, 0, n}], {n, 0, 18}] (* Michael De Vlieger, Aug 07 2017 *)
  • PARI
    C=binomial;
    a(n) = sum(k=0,n, sum(l=0,n, C(n,k)^2 * C(n,l) * C(k,l) * C(k+l,n) ));

Formula

a(0) = 1, a(1) = 3,
a(n+1) = ( (2*n+1)*(9*n^2+9*n+3)*a(n) + 27*n^3*a(n-1) ) / (n+1)^3.
a(n) ~ 3^(3*n/2 + 1) * (1+sqrt(3))^(2*n+1) / (2^(n + 5/2) * (Pi*n)^(3/2)). - Vaclav Kotesovec, Jul 10 2021
G.f.: hypergeom([1/12,5/12],[1],(12*x/(1-6*x-27*x^2))^3)^2/(1-6*x-27*x^2)^(1/2). - Mark van Hoeij, Nov 11 2022

A133370 Primes p such that p does not divide any term of the Apery sequence A005259 .

Original entry on oeis.org

2, 3, 7, 13, 23, 29, 43, 47, 53, 67, 71, 79, 83, 89, 101, 103, 107, 109, 113, 127, 131, 137, 149, 157, 167, 173, 199, 223, 229, 239, 263, 269, 277, 281, 311, 313, 317, 337, 349, 353, 359, 373, 383, 389, 397, 401, 409, 421, 449, 457, 461, 467, 479, 487, 491
Offset: 1

Views

Author

Philippe Deléham, Oct 27 2007

Keywords

Comments

Malik and Straub give arguments suggesting that this sequence is infinite. - N. J. A. Sloane, Aug 06 2017

Crossrefs

For primes that do not divide the terms of the sequences A000172, A005258, A002893, A081085, A006077, A093388, A125143, A229111, A002895, A290575, A290576, A005259 see A260793, A291275-A291284 and A133370 respectively.

Programs

  • Mathematica
    NeverDividesLucasSeqQ[a_, p_] := And @@ Table[Mod[a[n], p]>0, {n, 0, p-1}];
    A3[a_, b_, c_, n_ /; n < 0] = 0;
    A3[a_, b_, c_, 0] = 1;
    A3[a_, b_, c_, n_] := A3[a, b, c, n] = (((2n - 1)(a (n-1)^2 + a (n-1) + b)) A3[a, b, c, n-1] - c (n-1)^3 A3[a, b, c, n-2])/n^3;
    A3[a_, b_, c_, d_, n_ /; n < 0] = 0;
    Agamma[n_] := A3[17, 5, 1, n];
    Select[Range[1000], PrimeQ[#] && NeverDividesLucasSeqQ[Agamma, #]&] (* Jean-François Alcover, Aug 05 2018, copied from Amita Malik's notebook *)

Extensions

Terms a(16) onwards computed by Amita Malik - N. J. A. Sloane, Aug 21 2017

A291275 Primes p such that p does not divide any term of the Apéry-like sequence A005258.

Original entry on oeis.org

2, 5, 13, 17, 29, 37, 41, 61, 73, 89, 101, 109, 137, 149, 173, 181, 197, 229, 233, 269, 277, 313, 337, 349, 353, 373, 397, 401, 409, 433, 457, 461, 541, 557, 601, 613, 641, 661, 673, 677, 701, 709, 733, 761, 769, 797, 821, 829, 853, 857, 877, 929, 941, 977
Offset: 1

Views

Author

N. J. A. Sloane, Aug 21 2017

Keywords

Crossrefs

For primes that do not divide the terms of the sequences A000172, A005258, A002893, A081085, A006077, A093388, A125143, A229111, A002895, A290575, A290576, A005259 see A260793, A291275-A291284 and A133370 respectively.

Programs

  • Mathematica
    maxPrime = 977;
    maxPi = PrimePi @ maxPrime;
    okQ[p_] := AllTrue[Range[3 maxPi (* coeff 3 is empirical *)], GCD[HypergeometricPFQ[{# + 1, -#, -#}, {1, 1}, 1], p] == 1&];
    Select[Prime[Range[maxPi]], okQ] (* Jean-François Alcover, Jan 13 2020 *)

A291284 Primes p such that p does not divide any term of the Apery-like sequence A290576.

Original entry on oeis.org

2, 5, 7, 13, 17, 19, 29, 37, 43, 47, 59, 61, 67, 71, 83, 89, 101, 109, 127, 139, 149, 167, 173, 191, 211, 233, 239, 241, 251, 257, 271, 277, 281, 307, 311, 313, 331, 337, 347, 349, 353, 359, 373, 379, 383, 409, 419, 421, 431, 433, 443
Offset: 1

Views

Author

N. J. A. Sloane, Aug 21 2017

Keywords

Crossrefs

For primes that do not divide the terms of the sequences A000172, A005258, A002893, A081085, A006077, A093388, A125143, A229111, A002895, A290575, A290576, A005259 see A260793, A291275-A291284 and A133370 respectively.

A260791 Type II primes (conjectured).

Original entry on oeis.org

5, 7, 13, 23, 31, 37, 47, 53, 71, 101, 103, 167, 181, 191, 197, 199, 223, 229, 263, 271, 293, 317, 349, 383, 397, 431, 439, 461, 479, 503, 509, 541, 557, 599, 607, 613, 647, 653, 677, 709, 719, 727, 733, 743, 751, 757, 797, 821, 823, 839, 877, 887, 911, 919, 991, 997
Offset: 1

Views

Author

N. J. A. Sloane, Aug 05 2015

Keywords

Comments

See Schulte et al. (2014) for the precise definition.

Crossrefs

A260792 Type III primes.

Original entry on oeis.org

2, 29, 41, 59, 61, 67, 73, 79, 107, 109, 127, 131, 149, 151, 157, 173, 179, 227, 239, 251, 257, 269, 277, 281, 311, 337, 359, 367, 373, 389, 421, 449, 457, 463, 467, 487, 521, 563, 571, 577, 593, 631, 659, 661, 683, 691, 701, 739, 761, 769, 773, 787, 809, 829, 853, 857, 863, 883, 907, 937, 941, 967, 971, 983
Offset: 1

Views

Author

N. J. A. Sloane, Aug 05 2015

Keywords

Comments

All primes that are neither in A260791 (Type II) nor in A260793 (type I).

Crossrefs

A291276 Primes p such that p does not divide any term of the Apery-like sequence A002893.

Original entry on oeis.org

2, 7, 13, 37, 61, 73, 109, 127, 157, 163, 193, 211, 223, 229, 271, 283, 307, 313, 331, 337, 349, 367, 379, 409, 421, 433, 463, 487, 499, 523, 577, 607, 613, 619, 631, 661, 673, 691, 727, 733, 751, 757, 769, 787, 823, 829, 853, 883, 907, 919, 1021, 1039
Offset: 1

Views

Author

N. J. A. Sloane, Aug 21 2017

Keywords

Crossrefs

For primes that do not divide the terms of the sequences A000172, A005258, A002893, A081085, A006077, A093388, A125143, A229111, A002895, A290575, A290576, A005259 see A260793, A291275-A291284 and A133370 respectively.

A291277 Primes p such that p does not divide any term of the Apery-like sequence A081085.

Original entry on oeis.org

3, 11, 17, 19, 43, 59, 73, 83, 89, 107, 179, 211, 227, 233, 241, 257, 307, 331, 337, 379, 401, 409, 419, 433, 449, 457, 467, 521, 547, 563, 577, 587, 593, 601, 619, 641, 643, 683, 691, 739, 761, 769, 811, 827, 859, 881, 883, 929, 937, 947, 953
Offset: 1

Views

Author

N. J. A. Sloane, Aug 21 2017

Keywords

Crossrefs

For primes that do not divide the terms of the sequences A000172, A005258, A002893, A081085, A006077, A093388, A125143, A229111, A002895, A290575, A290576, A005259 see A260793, A291275-A291284 and A133370 respectively.

A291278 Primes p such that p does not divide any term of the Apery-like sequence A006077.

Original entry on oeis.org

2, 5, 13, 17, 29, 37, 41, 61, 73, 97, 101, 113, 137, 149, 157, 173, 181, 197, 229, 241, 257, 277, 313, 317, 349, 353, 389, 409, 421, 433, 449, 457, 461, 509, 541, 569, 577, 593, 613, 641, 653, 661, 673, 709, 757, 761, 769, 797, 809, 829, 853, 857
Offset: 1

Views

Author

N. J. A. Sloane, Aug 21 2017

Keywords

Crossrefs

For primes that do not divide the terms of the sequences A000172, A005258, A002893, A081085, A006077, A093388, A125143, A229111, A002895, A290575, A290576, A005259 see A260793, A291275-A291284 and A133370 respectively.
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