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.

Previous Showing 21-27 of 27 results.

A244136 Triangle read by rows: coefficients T(n,k) of a binomial decomposition of n^n as Sum(k=0..n)T(n,k)*binomial(n,k).

Original entry on oeis.org

1, 0, 1, 0, 1, 2, 0, 4, 2, 9, 0, 27, 8, 9, 64, 0, 256, 54, 36, 64, 625, 0, 3125, 512, 243, 256, 625, 7776, 0, 46656, 6250, 2304, 1728, 2500, 7776, 117649, 0, 823543, 93312, 28125, 16384, 16875, 31104, 117649, 2097152, 0, 16777216, 1647086, 419904, 200000, 160000, 209952, 470596, 2097152, 43046721
Offset: 0

Views

Author

Stanislav Sykora, Jun 22 2014

Keywords

Comments

T(n,k)=(k)^(k-1)*(n-k)^(n-k) for k>0, while T(n,0)=0^n by convention.

Examples

			The first rows of the triangle are:
1,
0, 1,
0, 1, 2,
0, 4, 2, 9,
0, 27, 8, 9, 64,
0, 256, 54, 36, 64, 625,
		

Crossrefs

Programs

  • PARI
    seq(nmax, b)={my(v, n, k, irow);
    v = vector((nmax+1)*(nmax+2)/2); v[1]=1;
    for(n=1, nmax, irow=1+n*(n+1)/2; v[irow]=0;
      for(k=1, n, v[irow+k]=(-k*b)^(k-1)*(n+k*b)^(n-k); ); );
    return(v); }
    a=seq(100,-1);

A244137 Triangle read by rows: terms T(n,k) of a binomial decomposition of n^n as Sum(k=0..n)T(n,k).

Original entry on oeis.org

1, 0, 1, 0, 2, 2, 0, 12, 6, 9, 0, 108, 48, 36, 64, 0, 1280, 540, 360, 320, 625, 0, 18750, 7680, 4860, 3840, 3750, 7776, 0, 326592, 131250, 80640, 60480, 52500, 54432, 117649, 0, 6588344, 2612736, 1575000, 1146880, 945000, 870912, 941192, 2097152
Offset: 0

Views

Author

Stanislav Sykora, Jun 22 2014

Keywords

Comments

T(n,k)=(k)^(k-1)*(n-k)^(n-k)*binomial(n,k) for k>0, while T(n,0)=0^n by convention.
There are many binomial decompositions of n^n, some with all terms positive like this one (see A243203). However, for every n, the terms corresponding to k=1..n in this one are exceptionally similar in value (at least on log scale).

Examples

			First rows of the triangle, all summing up to n^n:
1,
0, 1,
0, 2, 2,
0, 12, 6, 9,
0, 108, 48, 36, 64,
0, 1280, 540, 360, 320, 625,
		

Crossrefs

Programs

  • PARI
    seq(nmax, b)={my(v, n, k, irow);
    v = vector((nmax+1)*(nmax+2)/2); v[1]=1;
    for(n=1, nmax, irow=1+n*(n+1)/2; v[irow]=0;
      for(k=1, n, v[irow+k]=(-k*b)^(k-1)*(n+k*b)^(n-k)*binomial(n, k); ); );
    return(v); }
    a=seq(100,-1);

A244138 Triangle read by rows: coefficients T(n,k) of a binomial decomposition of n*(n-1) as Sum(k=0..n)T(n,k)*binomial(n,k).

Original entry on oeis.org

0, 0, 0, 0, 0, 2, 0, 0, 4, -6, 0, 0, 8, -18, 36, 0, 0, 16, -54, 144, -320, 0, 0, 32, -162, 576, -1600, 3750, 0, 0, 64, -486, 2304, -8000, 22500, -54432, 0, 0, 128, -1458, 9216, -40000, 135000, -381024, 941192, 0, 0, 256, -4374, 36864, -200000, 810000, -2667168, 7529536, -18874368
Offset: 0

Views

Author

Stanislav Sykora, Jun 22 2014

Keywords

Comments

T(n,k)=k*(1-k)^(k-2)*k^(n-k) for k>1, while T(n,0)=T(n,1)=0 by convention.

Examples

			The first rows of the triangle are:
0,
0, 0,
0, 0, 2,
0, 0, 4, -6,
0, 0, 8, -18, 36,
0, 0, 16, -54, 144, -320,
0, 0, 32, -162, 576, -1600, 3750,
		

Crossrefs

Programs

  • PARI
    seq(nmax)={my(v,n,k,irow);
    v = vector((nmax+1)*(nmax+2)/2);v[1]=0;
    for(n=1,nmax,irow=1+n*(n+1)/2;v[irow]=0;v[irow+1]=0;
      for(k=2,n,v[irow+k]=k*(1-k)^(k-2)*k^(n-k);););
    return(v);}
    a=seq(100);

A244139 Triangle read by rows: terms T(n,k) of a binomial decomposition of n*(n-1) as Sum(k=0..n)T(n,k).

Original entry on oeis.org

0, 0, 0, 0, 0, 2, 0, 0, 12, -6, 0, 0, 48, -72, 36, 0, 0, 160, -540, 720, -320, 0, 0, 480, -3240, 8640, -9600, 3750, 0, 0, 1344, -17010, 80640, -168000, 157500, -54432, 0, 0, 3584, -81648, 645120, -2240000, 3780000, -3048192, 941192, 0, 0, 9216, -367416, 4644864, -25200000, 68040000, -96018048, 67765824, -18874368
Offset: 0

Views

Author

Stanislav Sykora, Jun 22 2014

Keywords

Comments

T(n,k)=k*(1-k)^(k-2)*k^(n-k)*binomial(n,k) for k>1, while T(n,0)=T(n,1)=0 by convention.

Examples

			First rows of the triangle, all summing up to n*(n-1):
0,
0, 0,
0, 0, 2,
0, 0, 12, -6,
0, 0, 48, -72, 36,
0, 0, 160, -540, 720, -320,
0, 0, 480, -3240, 8640, -9600, 3750,
		

Crossrefs

Programs

  • PARI
    seq(nmax)={my(v, n, k, irow);
    v = vector((nmax+1)*(nmax+2)/2); v[1]=0;
    for(n=1, nmax, irow=1+n*(n+1)/2; v[irow]=0; v[irow+1]=0;
      for(k=2, n, v[irow+k]=k*(1-k)^(k-2)*k^(n-k)*binomial(n,k); ); );
    return(v); }
    a=seq(100);

A244140 Triangle read by rows: coefficients T(n,k) of a binomial decomposition of n*(-1)^n as Sum(k=0..n)T(n,k)*binomial(n,k).

Original entry on oeis.org

0, 0, -1, 0, 0, 2, 0, 0, 0, -3, 0, 0, 0, -3, 16, 0, 0, 0, -3, 32, -135, 0, 0, 0, -3, 64, -405, 1536, 0, 0, 0, -3, 128, -1215, 6144, -21875, 0, 0, 0, -3, 256, -3645, 24576, -109375, 373248, 0, 0, 0, -3, 512, -10935, 98304, -546875, 2239488, -7411887, 0, 0, 0, -3, 1024, -32805, 393216, -2734375, 13436928, -51883209, 167772160
Offset: 0

Views

Author

Stanislav Sykora, Jun 23 2014

Keywords

Comments

T(n,k)=(-1)^k*k*(k-2)^(n-2) for k>1, while T(n,0)=0 and T(1,1)=-0^(n-1) by convention.

Examples

			The first rows of the triangle are:
0,
0, -1,
0, 0, 2,
0, 0, 0, -3,
0, 0, 0, -3, 16,
0, 0, 0, -3, 32, -135,
0, 0, 0, -3, 64, -405, 1536,
0, 0, 0, -3, 128, -1215, 6144, -21875,
		

Crossrefs

Programs

  • PARI
    seq(nmax)={my(v,n,k,irow);
    v = vector((nmax+1)*(nmax+2)/2);v[1]=0;
    for(n=1,nmax,irow=1+n*(n+1)/2;
      v[irow]=0;if(n==1,v[irow+1]=-1,v[irow+1]=0);
    for(k=2,n,v[irow+k]=(-1)^k*k*(k-2)^(n-2);););
    return(v);}
    a=seq(100);

A244141 Triangle read by rows: terms T(n,k) of a binomial decomposition of n*(-1)^n as Sum(k=0..n)T(n,k).

Original entry on oeis.org

0, 0, -1, 0, 0, 2, 0, 0, 0, -3, 0, 0, 0, -12, 16, 0, 0, 0, -30, 160, -135, 0, 0, 0, -60, 960, -2430, 1536, 0, 0, 0, -105, 4480, -25515, 43008, -21875, 0, 0, 0, -168, 17920, -204120, 688128, -875000, 373248, 0, 0, 0, -252, 64512, -1377810, 8257536, -19687500, 20155392, -7411887
Offset: 0

Views

Author

Stanislav Sykora, Jun 23 2014

Keywords

Comments

T(n,k)=(-1)^k*k*(k-2)^(n-2)*binomial(n,k) for k>1, while T(n,0)=0 and T(1,1)=-0^(n-1) by convention.

Examples

			First rows of the triangle, all summing up to n*(-1)^n:
0,
0, -1,
0, 0, 2,
0, 0, 0, -3,
0, 0, 0, -12, 16,
0, 0, 0, -30, 160, -135,
0, 0, 0, -60, 960, -2430, 1536,
		

Crossrefs

Programs

  • PARI
    seq(nmax)={my(v, n, k, irow);
    v = vector((nmax+1)*(nmax+2)/2); v[1]=0;
    for(n=1, nmax, irow=1+n*(n+1)/2;
      v[irow]=0; if(n==1, v[irow+1]=-1, v[irow+1]=0);
    for(k=2, n, v[irow+k]=(-1)^k*k*(k-2)^(n-2)*binomial(n,k); ); );
    return(v); }
    a=seq(100);

A244143 Triangle read by rows: terms T(n,k) of a binomial decomposition of n as Sum(k=0..n)T(n,k).

Original entry on oeis.org

0, 0, 1, 0, 0, 2, 0, 0, 18, -15, 0, 0, 108, -300, 196, 0, 0, 540, -3750, 6860, -3645, 0, 0, 2430, -37500, 144060, -196830, 87846, 0, 0, 10206, -328125, 2352980, -6200145, 6764142, -2599051, 0, 0, 40824, -2625000, 32941720, -148803480, 297622248, -270301304, 91125000
Offset: 0

Views

Author

Stanislav Sykora, Jun 23 2014

Keywords

Comments

T(n,k)=(-1)^k*k*(2*k-1)^(n-2)*binomial(n,k) for k>1, while T(n,0)=0 and T(1,1)=0^(n-1) by convention.

Examples

			First rows of the triangle, all summing up to n:
0,
0, 1,
0, 0, 2,
0, 0, 18, -15,
0, 0, 108, -300, 196,
0, 0, 540, -3750, 6860, -3645,
		

Crossrefs

Programs

  • PARI
    seq(nmax)={my(v, n, k, irow);
    v = vector((nmax+1)*(nmax+2)/2); v[1]=0;
    for(n=1, nmax, irow=1+n*(n+1)/2;
      v[irow]=0; if(n==1, v[irow+1]=1, v[irow+1]=0);
    for(k=2, n, v[irow+k]=(-1)^k*k*(2*k-1)^(n-2)*binomial(n,k); ); );
    return(v); }
    a=seq(100);
Previous Showing 21-27 of 27 results.