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.

A137153 Triangle, read by rows, where T(n,k) = C(2^k + n-k-1, n-k).

Original entry on oeis.org

1, 1, 1, 1, 2, 1, 1, 3, 4, 1, 1, 4, 10, 8, 1, 1, 5, 20, 36, 16, 1, 1, 6, 35, 120, 136, 32, 1, 1, 7, 56, 330, 816, 528, 64, 1, 1, 8, 84, 792, 3876, 5984, 2080, 128, 1, 1, 9, 120, 1716, 15504, 52360, 45760, 8256, 256, 1, 1, 10, 165, 3432, 54264, 376992, 766480, 357760, 32896
Offset: 0

Views

Author

Paul D. Hanna, Jan 24 2008

Keywords

Comments

Matrix inverse is A137156.
T(n,k) is the number of relations between a set of k distinguishable elements and a set of n-k indistinguishable elements. - Isaac R. Browne, Jun 04 2025

Examples

			Triangle begins:
  1;
  1,  1;
  1,  2,   1;
  1,  3,   4,    1;
  1,  4,  10,    8,     1;
  1,  5,  20,   36,    16,      1;
  1,  6,  35,  120,   136,     32,      1;
  1,  7,  56,  330,   816,    528,     64,      1;
  1,  8,  84,  792,  3876,   5984,   2080,    128,     1;
  1,  9, 120, 1716, 15504,  52360,  45760,   8256,   256,   1;
  1, 10, 165, 3432, 54264, 376992, 766480, 357760, 32896, 512, 1;
  ...
		

Crossrefs

Cf. A137154 (row sums), A137155 (antidiagonal sums), A060690 (central terms); A137156 (matrix inverse).
Cf. A092056 (same with reflected rows).

Programs

  • Mathematica
    Table[Binomial[2^k+n-k-1,n-k],{n,0,10},{k,0,n}]//Flatten (* Harvey P. Dale, Mar 06 2017 *)
  • PARI
    {T(n,k)=binomial(2^k+n-k-1,n-k)}
    for(n=0,10,for(k=0,n,print1(T(n,k),", "));print(""))
    
  • PARI
    {T(n, k) = polcoeff(1/(1-x+x*O(x^n))^(2^k), n-k)}
    for(n=0,10,for(k=0,n,print1(T(n,k),", "));print(""))

A137157 G.f.: 1 = Sum_{n>=0} a(n)*x^n/(1+x)^(2*2^n).

Original entry on oeis.org

1, 2, 5, 24, 239, 4920, 206727, 17568408, 3003763243, 1030272816360, 707851744149198, 973425618916674288, 2678332881795756783639, 14741522294008025924154864, 162290544340043699103996962253, 3573515596966915773419766367302288, 157376160486791180710467411977740266927
Offset: 0

Views

Author

Paul D. Hanna, Jan 24 2008

Keywords

Comments

Equals unsigned column 1 of triangle A137156.

Crossrefs

Programs

  • PARI
    {a(n)=polcoeff(1-sum(k=0, n-1, a(k)*x^k/(1+x+x*O(x^n))^(2^(k+1)) ), n)}

Extensions

a(15)-a(16) from Alois P. Heinz, Jan 04 2023

A137158 G.f.: 1 = Sum_{n>=0} a(n)*x^n/(1+x)^(4*2^n).

Original entry on oeis.org

1, 4, 22, 228, 4749, 200240, 17034964, 2913479848, 999402129243, 686662003846640, 944294243796543974, 2598186366278914473948, 14300408328085246335179009, 157434326611214704329370130880
Offset: 0

Views

Author

Paul D. Hanna, Jan 24 2008

Keywords

Comments

Equals unsigned column 2 of triangle A137156.

Crossrefs

Programs

  • PARI
    {a(n)=polcoeff(1-sum(k=0, n-1, a(k)*x^k/(1+x+x*O(x^n))^(2^(k+2)) ), n)}

A137159 G.f.: 1 = Sum_{n>=0} a(n)*x^n/(1+x)^(8*2^n).

Original entry on oeis.org

1, 8, 92, 1976, 84086, 7173240, 1227862380, 421296930984, 289484024512093, 398106386971472608, 1095381029276651137560, 6028986377761538637043792, 66373632185586959347740452492, 1461497816340787260620205149915824
Offset: 0

Views

Author

Paul D. Hanna, Jan 24 2008

Keywords

Comments

Equals unsigned column 3 of triangle A137156.

Crossrefs

Programs

  • PARI
    {a(n)=polcoeff(1-sum(k=0, n-1, a(k)*x^k/(1+x+x*O(x^n))^(2^(k+3)) ), n)}

A137160 G.f.: 1 = Sum_{n>=0} a(n)*x^n*(1-x)/(1+x)^(2^n).

Original entry on oeis.org

1, 2, 4, 12, 64, 664, 13856, 584668, 49751520, 8509625760, 2919099754336, 2005648412219832, 2758163973596156000, 7588978611071894509464, 41769719229784446295570112, 459846172005153447271276789620
Offset: 0

Views

Author

Paul D. Hanna, Jan 24 2008

Keywords

Comments

Equals the unsigned row sums of triangle A137156.

Crossrefs

Programs

  • PARI
    {a(n)=polcoeff(1-sum(k=0, n-1, a(k)*x^k*(1-x)/(1+x+x*O(x^n))^(2^k) ), n)}

A137154 a(n) = Sum_{k=0..n} binomial(2^k + n-k-1, n-k); equals the row sums of triangle A137153.

Original entry on oeis.org

1, 2, 4, 9, 24, 79, 331, 1803, 12954, 123983, 1592513, 27604172, 648528166, 20722205191, 903019659239, 53792176322629, 4388683843024734, 491232972054490915, 75545748143323475653, 15984344095578889888206
Offset: 0

Views

Author

Paul D. Hanna, Jan 24 2008

Keywords

Comments

Matrix inverse of A137153 is A137156.

Crossrefs

Programs

  • Mathematica
    Table[Sum[Binomial[2^(n-k) + k - 1, k], {k, 0, n}], {n, 0, 20}] (* Vaclav Kotesovec, Jan 23 2021 *)
  • PARI
    a(n)=sum(k=0,n,binomial(2^k+n-k-1,n-k))
    
  • PARI
    {a(n)=local(A=sum(k=0,n,x^k/(1-x+x*O(x^n))^(2^k)));polcoeff(A,n)} \\ Paul D. Hanna, Sep 15 2009

Formula

G.f.: Sum_{n>=0} x^n/(1-x)^(2^n). - Paul D. Hanna, Sep 15 2009
G.f.: Sum_{n>=0} ( (-log(1 - x))^n / n! ) / (1 - 2^n*x). - Paul D. Hanna, Jan 23 2021
Showing 1-6 of 6 results.