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 1-6 of 6 results.

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

A136463 Diagonal of square array A136462: a(n) = C((n+1)*2^(n-1), n) for n>=0.

Original entry on oeis.org

1, 2, 15, 560, 91390, 61124064, 163995687856, 1756185841659392, 75079359427627897200, 12831653340946454374300160, 8777916355714456994772455584000, 24054320541767107204031746600673906688
Offset: 0

Views

Author

Paul D. Hanna, Dec 31 2007

Keywords

Comments

a(n) is divisible by (n+1) for n>=0: a(n)/(n+1) = A136464(n).

Crossrefs

Programs

  • Mathematica
    Table[Binomial[(n+1)2^(n-1),n],{n,0,15}]  (* Harvey P. Dale, Apr 20 2011 *)
  • PARI
    a(n)=binomial((n+1)*2^(n-1),n)
    
  • PARI
    /* a(n) = Coefficient of x^n in series: */
    a(n)=polcoeff(sum(i=0,n,((n+1)/2)^i*log(1+2^i*x +x*O(x^n))^i/i!),n)

Formula

a(n) = [x^n] Sum_{i>=0} ((n+1)/2)^i * log(1 + 2^i*x)^i/i!.
a(n) is found in row n, column 0, of matrix power A136467^(n+1) for n>=0.
a(n) ~ exp(n+1) * 2^(n*(n-1)) / sqrt(2*Pi*n). - Vaclav Kotesovec, Jul 02 2016

A136466 Row 2 of square array A136462: a(n) = C(3*2^(n-1), n) for n>=0.

Original entry on oeis.org

1, 3, 15, 220, 10626, 1712304, 927048304, 1708566412608, 10895665708319184, 244373929798154341120, 19561373281624772727757056, 5658395223117478029148167447552, 5975982733408602667847206514763365888
Offset: 0

Views

Author

Paul D. Hanna, Dec 31 2007

Keywords

Comments

a(n) is found in row n, column 0, of matrix cube A136467^3 for n>=0.

Crossrefs

Cf. A136462; other rows: A136465, A014070, A101346; A136467.

Programs

  • Mathematica
    Table[Binomial[3*2^(n-1),n], {n,0,15}] (* Vaclav Kotesovec, Jul 02 2016 *)
  • PARI
    a(n)=binomial(3*2^(n-1),n)
    
  • PARI
    /* T(n,k) = Coefficient of x^k in series: */ a(n)=polcoeff(sum(i=0,n,(3/2)^i*log(1+2^i*x +x*O(x^n))^i/i!),n)

Formula

a(n) = [x^n] Sum_{i>=0} (3/2)^i * log(1 + 2^i*x)^i/i!.
a(n) ~ 3^n * 2^(n*(n-1)) / n!. - Vaclav Kotesovec, Jul 02 2016

A136467 Triangle T, read by rows, where column 0 of T^m equals C(m*2^(n-1), n) as n=0,1,2,3,..., for all m.

Original entry on oeis.org

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, 1429702652400, 71889350288384, 83889221697536, 19373156990976, 1055047811072, 13257146368, 34865152, 16384, 1, 11288510714272000, 812123016027521024, 1022353118549770240, 258404578922332160, 15923445036482560, 238096880762880, 803108552704, 549453824, 65536, 1
Offset: 0

Views

Author

Paul D. Hanna, Dec 31 2007

Keywords

Comments

Column 0 of T^(n+1) = row n of square array A136462 defined by: A136462(n,k) = C((n+1)*2^(k-1), k);
T^n denotes the n-th matrix power of this triangle T = A136467.

Examples

			Triangle T 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;
1429702652400, 71889350288384, 83889221697536, 19373156990976, 1055047811072, 13257146368, 34865152, 16384, 1;
11288510714272000, 812123016027521024, 1022353118549770240, 258404578922332160, 15923445036482560, 238096880762880, 803108552704, 549453824, 65536, 1; ...
Column 0 of T^m is given by: [T^m](n,0) = C(m*2^(n-1), n) for n>=0.
Matrix square T^2 begins:
1;
2, 1;
6, 8, 1;
56, 128, 32, 1;
1820, 6048, 2176, 128, 1;
201376, 912128, 419328, 34816, 512, 1;
74974368, 449708544, 249300992, 26198016, 548864, 2048, 1;
94525795200, 739136655360, 477013868544, 59943682048, 1604059136, 8650752, 8192, 1; ...
in which column 0 equals [T^2](n,0) = C(2^n, n) for n>=0.
Matrix cube T^3 begins:
1;
3, 1;
15, 12, 1;
220, 288, 48, 1;
10626, 19696, 4800, 192, 1;
1712304, 4213376, 1333504, 76800, 768, 1;
927048304, 2927926016, 1133186048, 83992576, 1216512, 3072, 1;
1708566412608, 6784661682176, 3094826778624, 278193635328, 5216272384, 19267584, 12288, 1; ...
in which column 0 equals [T^3](n,0) = C(3*2^(n-1), n) for n>=0.
Matrix 4th power T^4 begins:
1;
4, 1;
28, 16, 1;
560, 512, 64, 1;
35960, 45888, 8448, 256, 1;
7624512, 12731904, 3066880, 135168, 1024, 1;
5423611200, 11434738688, 3390050304, 193953792, 2146304, 4096, 1;
13161885792000, 34243130728448, 12032434503680, 841005662208, 12133597184, 34078720, 16384, 1; ...
in which column 0 equals [T^4](n,0) = C(4*2^(n-1), n) for n>=0.
Matrix 5th power T^5 begins:
1;
5, 1;
45, 20, 1;
1140, 800, 80, 1;
91390, 88720, 13120, 320, 1;
24040016, 30268800, 5881600, 209920, 1280, 1;
21193254160, 33353694464, 8005555200, 372858880, 3338240, 5120, 1;
63815149590720, 122539734714368, 34967493738496, 1998561607680, 23429775360, 53084160, 20480, 1; ...
in which column 0 equals [T^5](n,0) = C(5*2^(n-1), n) for n>=0.
		

Crossrefs

Cf. columns: A136465, A136468, A136469; A136470 (matrix square); A136462.

Programs

  • PARI
    {T(n,k) = my(M=matrix(n+1,n+1,r,c,binomial(r*2^(c-2),c-1)),P); P=matrix(n+1,n+1,r,c,binomial((r+1)*2^(c-2),c-1));(P~*M~^-1)[n+1,k+1]}
    for(n=0,10,for(k=0,n,print1(T(n,k),", "));print(""))

Formula

Diagonals: T(n+1,n) = 4^n; T(n+2,n) = (2^(n+1) + n-1)*8^n.
T(n,k) is divisible by 2^((n-k)*k) for n>=k>=0.

A136470 Triangle T, read by rows, where column 0 of T^m = {C(m*2^n, n), n>=0} for all m.

Original entry on oeis.org

1, 2, 1, 6, 8, 1, 56, 128, 32, 1, 1820, 6048, 2176, 128, 1, 201376, 912128, 419328, 34816, 512, 1, 74974368, 449708544, 249300992, 26198016, 548864, 2048, 1, 94525795200, 739136655360, 477013868544, 59943682048, 1604059136, 8650752, 8192, 1, 409663695276000, 4132411271661568, 3028532448264192, 439222754869248, 14159357935616, 98723430400, 136839168, 32768, 1, 6208116950265950720, 80121787455478857728, 65415571433959456768, 10679727629898088448, 399723620798038016, 3391703461396480, 6141702569984, 2172649472, 131072, 1
Offset: 0

Views

Author

Paul D. Hanna, Dec 31 2007

Keywords

Comments

Column 0 of T^(n+1) = row 2n+1 of square array A136462 defined by: A136462(n,k) = C((n+1)*2^(k-1), k); T^n denotes the n-th matrix power of this triangle T = A136470.

Examples

			Triangle T begins:
1;
2, 1;
6, 8, 1;
56, 128, 32, 1;
1820, 6048, 2176, 128, 1;
201376, 912128, 419328, 34816, 512, 1;
74974368, 449708544, 249300992, 26198016, 548864, 2048, 1;
94525795200, 739136655360, 477013868544, 59943682048, 1604059136, 8650752, 8192, 1;
409663695276000, 4132411271661568, 3028532448264192, 439222754869248, 14159357935616, 98723430400, 136839168, 32768, 1; ...
Column 0 of T^m is given by: [T^m](n,0) = C(m*2^n, n) for n>=0.
		

Crossrefs

Cf. columns: A014070, A136471, A136472; A136467 (matrix square-root); A136462.

Programs

  • PARI
    {T(n,k)=local(M=matrix(n+1,n+1,r,c,binomial(r*2^(c-2),c-1)),P); P=matrix(n+1,n+1,r,c,binomial((r+1)*2^(c-2),c-1));((P~*M~^-1)^2)[n+1,k+1]}
    for(n=0, 10, for(k=0, n, print1(T(n, k), ", ")); print(""))

Formula

Equals the matrix square of triangle A136467.
Diagonals: T(n+1,n) = 2*4^n; T(n+2,n) = 2*8^n*(2^(n+2) + n-1).

A136464 C((n+1)*2^(n-1),n)/(n+1).

Original entry on oeis.org

1, 1, 5, 140, 18278, 10187344, 23427955408, 219523230207424, 8342151047514210800, 1283165334094645437430016, 797992395974041544979314144000, 2004526711813925600335978883389492224, 20319947544434703948516669537695298775460352
Offset: 0

Views

Author

Paul D. Hanna, Dec 31 2007

Keywords

Crossrefs

Programs

  • Magma
    [1] cat [(Binomial((n+1)*2^(n-1), n))/(n+1): n in [1..15]]; // Vincenzo Librandi, Nov 20 2014
  • Maple
    A136464:=n->binomial((n+1)*2^(n-1),n)/(n+1): seq(A136464(n), n=0..15); # Wesley Ivan Hurt, Nov 19 2014
  • Mathematica
    Table[Binomial[(n + 1)*2^(n - 1), n]/(n + 1), {n, 0, 15}] (* Wesley Ivan Hurt, Nov 19 2014 *)
  • PARI
    a(n)=binomial((n+1)*2^(n-1),n)/(n+1)
    

Formula

a(n) = A136463(n)/(n+1).

Extensions

a(12) from Vincenzo Librandi, Nov 20 2014
Showing 1-6 of 6 results.