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 21-30 of 413 results. Next

A176488 Triangle T(n,k) = A008292(n+1,k+1) + A176487(n,k) - 1, 0<=k<=n.

Original entry on oeis.org

1, 1, 1, 1, 8, 1, 1, 23, 23, 1, 1, 54, 136, 54, 1, 1, 117, 612, 612, 117, 1, 1, 244, 2395, 4850, 2395, 244, 1, 1, 499, 8605, 31271, 31271, 8605, 499, 1, 1, 1010, 29242, 176522, 312448, 176522, 29242, 1010, 1, 1, 2033, 95714, 910466, 2620832, 2620832, 910466
Offset: 0

Views

Author

Roger L. Bagula, Apr 19 2010

Keywords

Comments

Row sums are 1, 2, 10, 48, 246, 1460, 10130, 80752, 725998, 7258092, 79834602,....
Apparently the row sums obey (-45*n+124)*s(n) +(45*n^2+127*n-654)*s(n-1) +(-206*n^2+227*n+708)*s(n-2) +(303*n^2-869*n+458)*s(n-3) -2*(71*n-125)*(n-2)*s(n-4)=0. - R. J. Mathar, Jun 16 2015

Examples

			1;
1, 1;
1, 8, 1;
1, 23, 23, 1;
1, 54, 136, 54, 1;
1, 117, 612, 612, 117, 1;
1, 244, 2395, 4850, 2395, 244, 1;
1, 499, 8605, 31271, 31271, 8605, 499, 1;
1, 1010, 29242, 176522, 312448, 176522, 29242, 1010, 1;
1, 2033, 95714, 910466, 2620832, 2620832, 910466, 95714, 2033, 1;
1, 4080, 305317, 4407094, 19476436, 31448746, 19476436, 4407094, 305317, 4080, 1;
		

Crossrefs

Programs

  • Maple
    A176488 := proc(n,k)
        A008292(n+1,k+1)+A176487(n,k)-1 ;
    end proc: # R. J. Mathar, Jun 16 2015
  • Mathematica
    << DiscreteMath`Combinatorica`;
    t[n_, m_, 0] := Binomial[n, m];
    t[n_, m_, 1] := Eulerian[1 + n, m];
    t[n_, m_, q_] := t[n, m, q] = t[n, m, q - 1] + t[n, m, q - 2] - 1;
    Table[Flatten[Table[Table[t[n, m, q], {m, 0, n}], {n, 0, 10}]], {q, 0, 10}]

A014449 Numbers in the triangle of Eulerian numbers (A008292) that are not 1.

Original entry on oeis.org

4, 11, 11, 26, 66, 26, 57, 302, 302, 57, 120, 1191, 2416, 1191, 120, 247, 4293, 15619, 15619, 4293, 247, 502, 14608, 88234, 156190, 88234, 14608, 502, 1013, 47840, 455192, 1310354, 1310354, 455192, 47840, 1013, 2036, 152637, 2203488, 9738114
Offset: 1

Views

Author

Keywords

References

  • R. L. Graham, D. E. Knuth and O. Patashnik, Concrete Mathematics. Addison-Wesley, Reading, MA, 1990, p. 254.

Extensions

More terms from James Sellers
Offset corrected by Mohammad K. Azarian, Nov 19 2008

A038675 Triangle read by rows: T(n,k)=A(n,k)*binomial(n+k-1,n), where A(n,k) are the Eulerian numbers (A008292).

Original entry on oeis.org

1, 1, 3, 1, 16, 10, 1, 55, 165, 35, 1, 156, 1386, 1456, 126, 1, 399, 8456, 25368, 11970, 462, 1, 960, 42876, 289920, 393030, 95040, 1716, 1, 2223, 193185, 2577135, 7731405, 5525091, 741741, 6435, 1, 5020, 803440, 19411480, 111675850, 176644468
Offset: 1

Views

Author

Keywords

Comments

Andrews, Theory of Partitions, (1976), discussion of multisets.
Let a = a_1,a_2,...,a_n be a sequence on the alphabet {1,2,...,n}. Scan a from left to right and create an n-permutation by noting the POSITION of the elements as you come to them in order from least to greatest. See example. T(n,k) is the number of sequences that correspond to such a permutation having exactly n-k descents. [From Geoffrey Critzer, May 19 2010]

Examples

			1;
1,3;
1,16,10;
1,55,165,35;
1,156,1386,1456,126;
...
If a = 3,1,1,2,4,3 the corresponding 6-permutation is 2,3,4,1,6,5 because the first 1 is in the 2nd position, the second 1 is in the 3rd position,the 2 is in the 4th position, the first 3 is in the first position, the next 3 is in the 6th position and the 4 is in the 5th position of the sequence a. [From _Geoffrey Critzer_, May 19 2010]
		

References

  • R. L. Graham, D. E. Knuth and O. Patashnik, Concrete Mathematics, 2nd edition, Addison-Wesley, Reading, Mass., 1994, p. 269 (Worpitzky's identity).
  • Miklos Bona, Combinatorics of Permutations,Chapman and Hall,2004,page 6. [From Geoffrey Critzer, May 19 2010]

Crossrefs

Row sums yield A000312 (Worpitzky's identity).
Cf. A008292.

Programs

  • Maple
    A:=(n,k)->sum((-1)^j*(k-j)^n*binomial(n+1,j),j=0..k): T:=(n,k)->A(n,k)*binomial(n+k-1,n): seq(seq(T(n,k),k=1..n),n=1..10);
  • Mathematica
    Table[Table[Eulerian[n, k] Binomial[n + k, n], {k, 0, n - 1}], {n, 1,10}] (* Geoffrey Critzer, Jun 13 2013 *)

Extensions

More terms from Emeric Deutsch, May 08 2004

A085503 Sub-triangle of A008292: take every second term of every second row.

Original entry on oeis.org

1, 1, 1, 1, 66, 1, 1, 1191, 1191, 1, 1, 14608, 156190, 14608, 1, 1, 152637, 9738114, 9738114, 152637, 1, 1, 1479726, 423281535, 2275172004, 423281535, 1479726, 1, 1, 13824739, 15041229521, 311387598411
Offset: 0

Views

Author

Roger L. Bagula, Dec 13 2010

Keywords

Examples

			{1},
{1, 1},
{1, 66, 1},
{1, 1191, 1191, 1},
{1, 14608, 156190, 14608, 1},
{1, 152637, 9738114, 9738114, 152637, 1},
		

Crossrefs

Cf. A008292.

Programs

  • Mathematica
    << DiscreteMath`Combinatorica`
    a = Table[Table[Eulerian[n + 1, 2*m], {m, 0, Floor[n/2]}], {n, 0, 20, 2}];
    Flatten[%]

A141689 Average of Eulerian numbers (A008292) and Pascal's triangle (A007318): t(n,m) = (A008292(n,m) + A007318(n,m))/2.

Original entry on oeis.org

1, 1, 1, 1, 3, 1, 1, 7, 7, 1, 1, 15, 36, 15, 1, 1, 31, 156, 156, 31, 1, 1, 63, 603, 1218, 603, 63, 1, 1, 127, 2157, 7827, 7827, 2157, 127, 1, 1, 255, 7318, 44145, 78130, 44145, 7318, 255, 1, 1, 511, 23938, 227638, 655240, 655240, 227638, 23938, 511, 1
Offset: 1

Views

Author

Roger L. Bagula, Sep 09 2008

Keywords

Comments

Row sums are: {1, 2, 5, 16, 68, 376, 2552, 20224, 181568, 1814656, ...}.
If Pascal's triangle and the Eulerian numbers are both fundamental arrays, then there should be a combinatorial set "between" them.

Examples

			{1},
{1, 1},
{1, 3, 1},
{1, 7, 7, 1},
{1, 15, 36, 15, 1},
{1, 31, 156, 156, 31, 1},
{1, 63, 603, 1218, 603, 63, 1},
{1, 127, 2157, 7827, 7827, 2157, 127, 1},
{1, 255, 7318, 44145, 78130, 44145, 7318, 255, 1},
{1, 511, 23938, 227638, 655240, 655240, 227638, 23938, 511, 1}
		

Crossrefs

Programs

  • Mathematica
    Table[Table[(Sum[(-1)^j Binomial[n + 1, j](k + 1 - j)^n, {j, 0, k + 1}] + Binomial[n - 1, k])/2, {k, 0, n - 1}], {n, 1, 10}]; Flatten[%]

Extensions

Edited by N. J. A. Sloane, Dec 13 2008

A141690 Triangle t(n,m) = 2*A008292(n+1,m+1) - A007318(n,m), a linear combination of Eulerian numbers and Pascal's triangle, 0 <= m <= n.

Original entry on oeis.org

1, 1, 1, 1, 6, 1, 1, 19, 19, 1, 1, 48, 126, 48, 1, 1, 109, 594, 594, 109, 1, 1, 234, 2367, 4812, 2367, 234, 1, 1, 487, 8565, 31203, 31203, 8565, 487, 1, 1, 996, 29188, 176412, 312310, 176412, 29188, 996, 1, 1, 2017, 95644, 910300, 2620582, 2620582, 910300
Offset: 0

Views

Author

Roger L. Bagula, Sep 09 2008

Keywords

Comments

Row sums are 1, 2, 8, 40, 224, 1408, 10016, 80512, 725504, 7257088, ... = 2*(n+1)! - 2^n.

Examples

			Triangle begins
  1;
  1,    1;
  1,    6,     1;
  1,   19,    19,      1;
  1,   48,   126,     48,       1;
  1,  109,   594,    594,     109,       1;
  1,  234,  2367,   4812,    2367,     234,      1;
  1,  487,  8565,  31203,   31203,    8565,    487,     1;
  1,  996, 29188, 176412,  312310,  176412,  29188,   996,    1;
  1, 2017, 95644, 910300, 2620582, 2620582, 910300, 95644, 2017, 1;
		

Crossrefs

Programs

  • Maple
    A141690 := proc(n,m)
            2*A008292(n+1,m+1)-binomial(n,m) ;
    end proc: # R. J. Mathar, Jul 12 2012
  • Mathematica
    Table[Table[(2*Sum[(-1)^j Binomial[n + 1, j](k + 1 - j)^n, {j, 0, k + 1}] - Binomial[n - 1, k]), {k, 0, n - 1}], {n, 1, 10}]; Flatten[%]

A143505 Triangle of coefficients of the polynomials x^(n - 1)*A(n,x + 1/x), where A(n,x) are the Eulerian polynomials of A008292.

Original entry on oeis.org

1, 1, 1, 1, 1, 4, 3, 4, 1, 1, 11, 14, 23, 14, 11, 1, 1, 26, 70, 104, 139, 104, 70, 26, 1, 1, 57, 307, 530, 973, 947, 973, 530, 307, 57, 1, 1, 120, 1197, 3016, 5970, 8568, 9549, 8568, 5970, 3016, 1197, 120, 1, 1, 247, 4300, 17101, 37105, 70474, 90069, 107241, 90069
Offset: 1

Views

Author

Roger L. Bagula and Gary W. Adamson, Oct 25 2008

Keywords

Comments

Row sums yield A000670 (without leading 1).

Examples

			Triangle begins:
   1;
   1,  1,   1;
   1,  4,   3,   4,   1;
   1, 11,  14,  23,  14,  11,   1;
   1, 26,  70, 104, 139, 104,  70,  26,   1;
   1, 57, 307, 530, 973, 947, 973, 530, 307, 57, 1;
    ... reformatted. - _Franck Maminirina Ramaharo_, Oct 25 2018
		

Crossrefs

Compare with A141720.
Cf. A008292.

Programs

  • Mathematica
    Table[CoefficientList[FullSimplify[ExpandAll[(1 - x - 1/x)^(n + 1)*x^(n - 1)*PolyLog[-n, x + 1/x]/(x + 1/x)]], x], {n, 1, 10}]//Flatten

Formula

Row n is generated by the polynomial (1 - x - 1/x)^(n + 1)*x^(n - 1)*Li(-n, x + 1/x)/(x + 1/x), where Li(n, z) is the polylogarithm function.
E.g.f.: (exp(x*y) - exp((1 + x^2)*y))/(x*exp((1 + x^2)*y) - (1 + x^2)*exp(x*y)). - Franck Maminirina Ramaharo, Oct 25 2018

Extensions

Edited and new name by Franck Maminirina Ramaharo, Oct 25 2018

A157117 Triangle T(n, k) = f(n, k) + f(n, n-k), where f(n, k) = A008292(n*k + 1, n-k) if k <= n otherwise A008292(n*(n-k), k), read by rows.

Original entry on oeis.org

2, 1, 1, 1, 8, 1, 1, 131, 131, 1, 1, 8204, 29216, 8204, 1, 1, 2097187, 44136233, 44136233, 2097187, 1, 1, 2147483736, 846839476071, 503464582368, 846839476071, 2147483736, 1, 1, 8796093022411, 150092195453359483, 288159195861579519, 288159195861579519, 150092195453359483, 8796093022411, 1
Offset: 0

Views

Author

Roger L. Bagula, Feb 23 2009

Keywords

Examples

			  2;
  1,          1;
  1,          8,            1;
  1,        131,          131,            1;
  1,       8204,        29216,         8204,            1;
  1,    2097187,     44136233,     44136233,      2097187,          1;
  1, 2147483736, 846839476071, 503464582368, 846839476071, 2147483736, 1;
		

Crossrefs

Programs

  • Magma
    Eulerian:= func< n,k | (&+[(-1)^j*Binomial(n+1,j)*(k-j+1)^n: j in [0..k+1]]) >;
    f:= func< n,k | k le n select Eulerian(n*k+1,n-k) else Eulerian(n*(n-k)+1, k) >;
    A157117:= func< n,k | f(n,k) + f(n,n-k) >;
    [A157117(n,k): k in [0..n], n in [0..12]]; // G. C. Greubel, Jan 11 2022
    
  • Mathematica
    f[n_, k_]:= If[k<=n, Eulerian[n*k+1,n-k], Eulerian[n*(n-k)+1,k]];
    T[n_, k_]:= f[n,k] + f[n,n-k];
    Table[T[n, k], {n,0,10}, {k,0,n}]//Flatten (* modified by G. C. Greubel, Jan 11 2022 *)
  • Sage
    def Eulerian(n,k): return sum((-1)^j*binomial(n+1,j)*(k-j+1)^n for j in (0..k+1))
    def f(n,k): return Eulerian(n*k+1,n-k) if (kA157117(n,k): return f(n,k) + f(n,n-k)
    flatten([[A157117(n,k) for k in (0..n)] for n in (0..12)]) # G. C. Greubel, Jan 11 2022

Formula

T(n, k) = f(n, k) + f(n, n-k), where f(n, k) = A008292(n*k + 1, n-k) if k <= n otherwise A008292(n*(n-k), k).
T(n, n-k) = T(n, k).

Extensions

Edited by G. C. Greubel, Jan 11 2022

A159346 Triangle read by rows: every third term of every third row of A008292.

Original entry on oeis.org

1, 1, 1, 1, 2416, 1, 1, 455192, 455192, 1, 1, 45533450, 2275172004, 45533450, 1, 1, 3572085255, 3207483178157, 3207483178157, 3572085255, 1, 1, 251732291184, 2527925001876036, 37307713155613000, 2527925001876036, 251732291184, 1, 1, 16871482830550, 1454842842001939656
Offset: 0

Views

Author

Roger L. Bagula, Dec 13 2010

Keywords

Examples

			Triangle begins:
  {1},
  {1, 1},
  {1, 2416, 1},
  {1, 455192, 455192, 1},
  {1, 45533450, 2275172004, 45533450, 1},
  {1, 3572085255, 3207483178157, 3207483178157, 3572085255, 1},
  ...
		

Crossrefs

Programs

  • Mathematica
    << DiscreteMath`Combinatorica`
    k = 3;
    a = Table[Table[Eulerian[n + 1, k*m], {m, 0, Floor[n/k]}], {n, 0, 10*k,k}];
    Flatten[%]

Formula

T(n, k) = A008292(3*n+1, 3*k+1). - Jason Yuen, Feb 04 2025

Extensions

Edited by N. J. A. Sloane, Jan 01 2011

A014469 Triangular array formed from odd elements to right of middle of rows of the triangle of Eulerian numbers (A008292).

Original entry on oeis.org

1, 1, 11, 1, 1, 57, 1, 1191, 1, 15619, 4293, 247, 1, 1, 1013, 1, 152637, 1, 10187685, 478271, 4083, 1, 423281535, 1, 12843262863, 2571742175, 16369, 1, 311387598411, 15041229521, 13824739, 1, 6382798925475, 3207483178157, 782115518299
Offset: 1

Views

Author

Keywords

References

  • R. L. Graham, D. E. Knuth and O. Patashnik, Concrete Mathematics. Addison-Wesley, Reading, MA, 1990, p. 254.

Extensions

More terms from James Sellers
Previous Showing 21-30 of 413 results. Next