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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A132684 a(n) = binomial(2^n + n + 1, n).

Original entry on oeis.org

1, 4, 21, 220, 5985, 501942, 143218999, 145944307080, 542150225230185, 7398714129087308170, 372134605932348010322571, 69146263065062394421802892300, 47589861944854471977019273909187085
Offset: 0

Views

Author

Paul D. Hanna, Aug 26 2007

Keywords

Examples

			From _Paul D. Hanna_, Feb 25 2009: (Start)
G.f.: A(x) = 1 + 4*x + 21*x^2 + 220*x^3 + 5985*x^4 + 501942*x^5 +...
A(x) = 1/(1-x)^2 - log(1-2x)/(1-2x)^2 + log(1-4x)^2/((1-4x)^2*2!) - log(1-8x)^3/((1-8x)^2*3!) +- ... (End)
		

Crossrefs

Sequences of the form binomial(2^n +p*n +q, n): A136556 (0,-1), A014070 (0,0), A136505 (0,1), A136506 (0,2), A060690 (1,-1), A132683 (1,0), this sequence (1,1), A132685 (2,0), A132686 (2,1), A132687 (3,-1), A132688 (3,0), A132689 (3,1).
Cf. A136555.
Cf. A066384. - Paul D. Hanna, Feb 25 2009

Programs

  • Magma
    [Binomial(2^n +n+1, n): n in [0..20]]; // G. C. Greubel, Mar 14 2021
  • Maple
    A132684:= n-> binomial(2^n +n+1, n); seq(A132684(n), n=0..20); # G. C. Greubel, Mar 14 2021
  • Mathematica
    Table[Binomial[2^n+n+1,n],{n,0,20}] (* Harvey P. Dale, Nov 10 2011 *)
  • PARI
    a(n)=binomial(2^n+n+1,n)
    
  • PARI
    {a(n)=polcoeff(sum(m=0,n,(-log(1-2^m*x))^m/((1-2^m*x +x*O(x^n))^2*m!)),n)} \\ Paul D. Hanna, Feb 25 2009
    
  • Sage
    [binomial(2^n +n+1, n) for n in (0..20)] # G. C. Greubel, Mar 14 2021
    

Formula

a(n) = [x^n] 1/(1-x)^(2^n + 2).
G.f.: Sum_{n>=0} (-log(1 - 2^n*x))^n / ((1 - 2^n*x)^2*n!). - Paul D. Hanna, Feb 25 2009
a(n) ~ 2^(n^2) / n!. - Vaclav Kotesovec, Jul 02 2016

A132685 a(n) = binomial(2^n + 2*n, n).

Original entry on oeis.org

1, 4, 28, 364, 10626, 850668, 218618940, 198773423848, 669741609663270, 8493008777332033900, 405943250253048290447028, 72938914603968404495709630360, 49143490709866058459392200362497820
Offset: 0

Views

Author

Paul D. Hanna, Aug 26 2007

Keywords

Crossrefs

Sequences of the form binomial(2^n +p*n +q, n): A136556 (0,-1), A014070 (0,0), A136505 (0,1), A136506 (0,2), A060690 (1,-1), A132683 (1,0), A132684 (1,1), this sequence (2,0), A132686 (2,1), A132687 (3,-1), A132688 (3,0), A132689 (3,1).
Cf. A136555.

Programs

  • Magma
    [Binomial(2^n+2*n,n): n in [0..20]]; // G. C. Greubel, Mar 14 2021
  • Maple
    A132695:= n-> binomial(2^n +2*n,n); seq(A132685(n), n=0..20); # G. C. Greubel, Mar 14 2021
  • Mathematica
    Table[Binomial[2^n+2n,n],{n,0,20}] (* Harvey P. Dale, Jun 01 2016 *)
  • PARI
    a(n)=binomial(2^n+2*n,n)
    
  • Sage
    [binomial(2^n+2*n,n) for n in (0..20)] # G. C. Greubel, Mar 14 2021
    

Formula

a(n) = [x^n] 1/(1-x)^(2^n + n + 1).

A132686 a(n) = binomial(2^n + 2*n + 1, n).

Original entry on oeis.org

1, 5, 36, 455, 12650, 962598, 237093780, 209004408899, 689960224294614, 8639439963148103450, 409865407260324119340236, 73328394245057556170201283726, 49287010273876375495535472789937580
Offset: 0

Views

Author

Paul D. Hanna, Aug 26 2007

Keywords

Crossrefs

Sequences of the form binomial(2^n +p*n +q, n): A136556 (0,-1), A014070 (0,0), A136505 (0,1), A136506 (0,2), A060690 (1,-1), A132683 (1,0), A132684 (1,1), A132685 (2,0), this sequence (2,1), A132687 (3,-1), A132688 (3,0), A132689 (3,1).
Cf. A136555.

Programs

  • Magma
    [Binomial(2^n +2*n +1, n): n in [0..20]]; // G. C. Greubel, Mar 13 2021
  • Mathematica
    Table[Binomial[2^n +2*n +1, n], {n,0,20}] (* G. C. Greubel, Mar 13 2021 *)
  • PARI
    a(n)=binomial(2^n+2*n+1,n)
    
  • Sage
    [binomial(2^n +2*n +1, n) for n in (0..20)] # G. C. Greubel, Mar 13 2021
    

Formula

a(n) = [x^n] 1/(1-x)^(2^n + n + 2).

A132687 a(n) = binomial(2^n + 3*n - 1, n).

Original entry on oeis.org

1, 4, 36, 560, 17550, 1370754, 324540216, 267212177232, 822871715492970, 9728874233306696390, 442491588454024774291770, 76919746769405407508866898400, 50743487119356450255156023756871000
Offset: 0

Views

Author

Paul D. Hanna, Aug 26 2007

Keywords

Crossrefs

Sequences of the form binomial(2^n +p*n +q, n): A136556 (0,-1), A014070 (0,0), A136505 (0,1), A136506 (0,2), A060690 (1,-1), A132683 (1,0), A132684 (1,1), A132685 (2,0), A132686 (2,1), this sequence (3,-1), A132688 (3,0), A132689 (3,1).
Cf. A136555.

Programs

  • Magma
    [Binomial(2^n +3*n -1, n): n in [0..20]]; // G. C. Greubel, Mar 13 2021
  • Mathematica
    Table[Binomial[2^n+3n-1,n],{n,0,20}] (* Harvey P. Dale, Sep 07 2017 *)
  • PARI
    a(n)=binomial(2^n+3*n-1,n)
    
  • Sage
    [binomial(2^n +3*n -1, n) for n in (0..20)] # G. C. Greubel, Mar 13 2021
    

Formula

a(n) = [x^n] 1/(1-x)^(2^n + 2*n).

A132688 a(n) = binomial(2^n + 3*n, n).

Original entry on oeis.org

1, 5, 45, 680, 20475, 1533939, 350161812, 280384608504, 847073824772175, 9894081531608130857, 446730013630787463700695, 77328499046923986969058944720, 50891283683781760304442885961988100
Offset: 0

Views

Author

Paul D. Hanna, Aug 26 2007

Keywords

Crossrefs

Sequences of the form binomial(2^n +p*n +q, n): A136556 (0,-1), A014070 (0,0), A136505 (0,1), A136506 (0,2), A060690 (1,-1), A132683 (1,0), A132684 (1,1), A132685 (2,0), A132686 (2,1), A132687 (3,-1), this sequence (3,0), A132689 (3,1).
Cf. A136555.

Programs

  • Magma
    [Binomial(2^n +3*n, n): n in [0..20]]; // G. C. Greubel, Mar 13 2021
  • Mathematica
    Table[Binomial[2^n+3n,n],{n,0,20}] (* Harvey P. Dale, Oct 30 2018 *)
  • PARI
    a(n)=binomial(2^n+3*n,n)
    
  • Sage
    [binomial(2^n +3*n, n) for n in (0..20)] # G. C. Greubel, Mar 13 2021
    

Formula

a(n) = [x^n] 1/(1-x)^(2^n + 2*n + 1).

A132689 a(n) = binomial(2^n + 3*n + 1, n).

Original entry on oeis.org

1, 6, 55, 816, 23751, 1712304, 377447148, 294109729200, 871896500955975, 10061777828754031380, 451004941990890693018405, 77739225019650285306412710240, 51039474754930845750609669420261300
Offset: 0

Views

Author

Paul D. Hanna, Aug 26 2007

Keywords

Crossrefs

Sequences of the form binomial(2^n +p*n +q, n): A136556 (0,-1), A014070 (0,0), A136505 (0,1), A136506 (0,2), A060690 (1,-1), A132683 (1,0), A132684 (1,1), A132685 (2,0), A132686 (2,1), A132687 (3,-1), A132688 (3,0), this sequence (3,1).
Cf. A136555.

Programs

  • Magma
    [Binomial(2^n+3*n+1, n) : n in [0..15]]; // Wesley Ivan Hurt, Nov 20 2014
    
  • Maple
    A132689:=n->binomial(2^n+3*n+1, n): seq(A132689(n), n=0..15); # Wesley Ivan Hurt, Nov 20 2014
  • Mathematica
    Table[Binomial[2^n +3n +1, n], {n, 0, 15}] (* Wesley Ivan Hurt, Nov 20 2014 *)
  • PARI
    a(n)=binomial(2^n+3*n+1,n)
    
  • Sage
    [binomial(2^n +3*n+1, n) for n in (0..15)] # G. C. Greubel, Feb 15 2021

Formula

a(n) = [x^n] 1/(1-x)^(2^n + 2*n + 2).

A136393 a(n) = C(3^n,n).

Original entry on oeis.org

1, 3, 36, 2925, 1663740, 6774333588, 204208594169580, 47025847059877940202, 84798009611754271531960140, 1219731290030242386267605060168700, 141916030352038369973126553950792759280336
Offset: 0

Views

Author

Paul D. Hanna, Dec 28 2007

Keywords

Crossrefs

Cf. A014070 (C(2^n, n)).

Programs

  • Magma
    [Binomial(3^n,n): n in [0..25]]; // Vincenzo Librandi, Sep 13 2016
  • Mathematica
    Table[Binomial[3^n,n], {n,0,10}] (* Vaclav Kotesovec, Jul 02 2016 *)
  • PARI
    a(n)=binomial(3^n,n)
    
  • PARI
    /* G.f. A(x) as Sum of Series: */
    a(n)=polcoeff(sum(k=0,n,log(1+3^k*x +x*O(x^n))^k/k!),n)
    
  • PARI
    {a(n) = (1/n!) * sum(k=0, n, stirling(n, k, 1) * 3^(n*k) )}
    for(n=0, 20, print1(a(n), ", ")) \\ Paul D. Hanna, Feb 05 2023
    

Formula

G.f.: A(x) = Sum_{n>=0} log(1 + 3^n*x)^n / n!.
a(n) = (1/n!) * Sum_{k=0..n} Stirling1(n, k) * 3^(n*k). - Paul D. Hanna, Feb 05 2023
a(n) ~ 3^(n^2)/n!. - Vaclav Kotesovec, Jul 02 2016

A189981 E.g.f. satisfies: A(x) = Sum_{n>=0} log(1 + x*A(x)^n)^n/n!.

Original entry on oeis.org

1, 1, 2, 12, 120, 1600, 28500, 621138, 16017792, 480474720, 16390969920, 626786792280, 26584872779520, 1238524175509608, 62873918454756864, 3455537675553482400, 204449393824639488000, 12958008875933613962880
Offset: 0

Views

Author

Paul D. Hanna, May 03 2011

Keywords

Comments

The definition of the e.g.f. A(x) is an application of the identity:
* Sum_{n>=0} log(1 + q^n*x)^n/n! = Sum_{n>=0} binomial(q^n, n)*x^n at q = A(x).
Consider the function G(x) such that G(x) = 1 + x*G(x)^p, then
* G(x) = Sum_{n>=0} log(1 + x*G(x)^p)^n/n! (trivially), and
* G(x) = Sum_{n>=0} binomial(p*n+1,n)*x^n/(p*n+1) for fixed p;
does an analogous expression exist for the e.g.f. of this sequence?
Note that terms a(70)-a(83) are negative. - Vaclav Kotesovec, Jul 13 2014

Examples

			E.g.f.: A(x) = 1 + x + 2*x^2/2! + 12*x^3/3! + 120*x^4/4! + 1600*x^5/5! +...
where A(x) satisfies:
A(x) = 1 + log(1 + x*A(x)) + log(1 + x*A(x)^2)^2/2! + log(1 + x*A(x)^3)^3/3! +...
The e.g.f. also satisfies:
A(x) = 1 + A(x)*x + A(x)^2*(A(x)^2-1)*x^2/2! + A(x)^3*(A(x)^3-1)*(A(x)^3-2)*x^3/3! + A(x)^4*(A(x)^4-1)*(A(x)^4-2)*(A(x)^4-3)*x^4/4! +...+ binomial(A(x)^n, n)*x^n +...
		

Crossrefs

Programs

  • PARI
    {a(n)=local(A=1+x);for(i=1,n,A=sum(m=0,n,log(1+x*(A+x*O(x^n))^m)^m/m!));n!*polcoeff(A,n)}
    
  • PARI
    {a(n)=local(A=1+x);for(i=1,n,A=sum(m=0,n,binomial((A+x*O(x^n))^m,m)*x^m));n!*polcoeff(A,n)}
    
  • PARI
    {Stirling1(n, k)=n!*polcoeff(binomial(x, n), k)}
    {a(n)=local(A=1+x);for(i=1,n,A=sum(m=0,n,sum(k=0,m,Stirling1(m,k)*(A+x*O(x^n))^(m*k))*x^m/m!));n!*polcoeff(A,n)}

Formula

E.g.f. also satisfies:
(1) A(x) = Sum_{n>=0} binomial(A(x)^n, n) * x^n.
(2) A(x) = Sum_{n>=0} x^n * Sum_{k=0..n} Stirling1(n,k) * A(x)^(n*k)/n!.

A136462 Square table, read by antidiagonals, where T(n,k) = C((n+1)*2^(k-1), k) for n>=0, k>=0.

Original entry on oeis.org

1, 1, 1, 1, 2, 1, 1, 3, 6, 4, 1, 4, 15, 56, 70, 1, 5, 28, 220, 1820, 4368, 1, 6, 45, 560, 10626, 201376, 906192, 1, 7, 66, 1140, 35960, 1712304, 74974368, 621216192, 1, 8, 91, 2024, 91390, 7624512, 927048304, 94525795200, 1429702652400, 1, 9, 120, 3276, 194580, 24040016, 5423611200, 1708566412608, 409663695276000, 11288510714272000, 1, 10, 153, 4960, 367290, 61124064, 21193254160, 13161885792000, 10895665708319184, 6208116950265950720, 312268282598377321216
Offset: 0

Views

Author

Paul D. Hanna, Dec 31 2007

Keywords

Comments

Row n equals column 0 of matrix product A136467^(n+1) for n>=0.

Examples

			1,1,1,4,70,4368,906192,621216192,1429702652400,11288510714272000,...;
1,2,6,56,1820,201376,74974368,94525795200,409663695276000,...;
1,3,15,220,10626,1712304,927048304,1708566412608,...;
1,4,28,560,35960,7624512,5423611200,13161885792000,...;
1,5,45,1140,91390,24040016,21193254160,63815149590720,...;
1,6,66,2024,194580,61124064,64300886496,231207760388736,...;
1,7,91,3276,367290,134153712,163995687856,685581099291712,...;
1,8,120,4960,635376,264566400,368532802176,1756185841659392,...; ...
Triangle A136467 begins:
1;
1,1;
1,4,1;
4,32,16,1;
70,848,576,64,1;
4368,75648,62208,9216,256,1;
906192,22313216,21169152,3792896,143360,1024,1;
621216192,21827627008,23212261376,4793434112,223215616,2228224,4096,1;
such that row n of A136462 equals column 0 of A136467^(n+1).
		

Crossrefs

Cf. rows: A136465, A014070, A136466, A101346; A136463 (diagonal); A136467.

Programs

  • PARI
    {T(n,k)=binomial((n+1)*2^(k-1),k)}
    for(n=0,10,for(k=0,10,print1(T(n,k),", "));print(""))
    
  • PARI
    /* T(n,k) = Coefficient of x^k in series: */
    {T(n,k)=polcoeff(sum(i=0,k,((n+1)/2)^i*log(1+2^i*x +x*O(x^k))^i/i!),k)}
    for(n=0,10,for(k=0,10,print1(T(n,k),", "));print(""))

Formula

O.g.f. of row n: Sum_{k>=0} ((n+1)/2)^k * log(1 + 2^k*x)^k / k! = Sum_{k>=0} C((n+1)*2^(k-1), k) * x^k for n>=0.

Extensions

More terms and b-file added by Paul D. Hanna, Jul 02 2016

A136465 Row 0 of square array A136462: a(n) = C(2^(n-1), n) for n>=0.

Original entry on oeis.org

1, 1, 1, 4, 70, 4368, 906192, 621216192, 1429702652400, 11288510714272000, 312268282598377321216, 30813235422145714150738944, 11005261717918037175659349191168, 14391972654784168932973746746691440640, 69538271351155829150354851003285125277716480, 1250303357941919088313448625534941836891635347865600
Offset: 0

Views

Author

Paul D. Hanna, Dec 31 2007

Keywords

Comments

a(n) is found in row n, column 0, of triangle A136467 for n>=0.
For n > 0, number of increasing integer sequences 1 <= a_1 < ... < a_n <= 2^(n-1). - Charles R Greathouse IV, Aug 08 2010
The (n-1)-dimensional hypercube has 2^(n-1) corners. There are binomial(2^(n-1),n) ways of selecting a set of n corners. So a(n) is the number of simplices (hyper-tetrahedra) with vertices defined by a corner subset of a (n-1)-dimensional hypercube. (This count includes degenerate polytopes with zero volume.) - R. J. Mathar, Jan 16 2016

Examples

			From _Paul D. Hanna_, Sep 26 2010: (Start)
G.f.: A(x) = 1 + x + x^2 + 4*x^3 + 70*x^4 + 4368*x^5 +...
A(x) = 1 + log(1+2*x)/2 + log(1 + 2^2*x)^2/(2!*2^2) + log(1 + 2^3*x)^3/(3!*2^3) + log(1 + 2^4*x)^4/(4!*2^4) +... (End)
		

Crossrefs

Cf. A136462; other rows: A014070, A136466, A101346; A136467.

Programs

  • Mathematica
    Table[Binomial[2^(n-1),n], {n,0,15}] (* Vaclav Kotesovec, Jul 02 2016 *)
  • PARI
    {a(n)=binomial(2^(n-1),n)}
    for(n=0,20,print1(a(n),", "))
    
  • PARI
    /* a(n) = Coefficient of x^k in series: */
    {a(n)=polcoeff(sum(i=0,n,(1/2)^i*log(1+2^i*x +x*O(x^n))^i/i!),n)}
    for(n=0,20,print1(a(n),", "))
    
  • PARI
    {a(n)=polcoeff(sum(m=0,n,log(1+2^m*x+x*O(x^n))^m/(m!*2^m)),n)}
    for(n=0,20,print1(a(n),", ")) \\ Paul D. Hanna, Sep 26 2010

Formula

a(n) = [x^n] Sum_{i>=0} (1/2)^i * log(1 + 2^i*x)^i/i!.
O.g.f.: Sum_{n>=0} log(1 + 2^n*x)^n / (n!*2^n). - Paul D. Hanna, Sep 26 2010
a(n) ~ 2^(n*(n-1)) / n!. - Vaclav Kotesovec, Jul 02 2016
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