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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A176663 T(n, k) = [x^k] Sum_{j=0..n} j!*binomial(x, j), for 0 <= k <= n, triangle read by rows.

Original entry on oeis.org

1, 1, 1, 1, 0, 1, 1, 2, -2, 1, 1, -4, 9, -5, 1, 1, 20, -41, 30, -9, 1, 1, -100, 233, -195, 76, -14, 1, 1, 620, -1531, 1429, -659, 161, -20, 1, 1, -4420, 11537, -11703, 6110, -1799, 302, -27, 1, 1, 35900, -98047, 106421, -61174, 20650, -4234, 519, -35, 1
Offset: 0

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Author

Roger L. Bagula, Apr 23 2010

Keywords

Examples

			Triangle starts:
  {1},
  {1,       1},
  {1,       0,      1},
  {1,       2,     -2,        1},
  {1,      -4,      9,       -5,      1},
  {1,      20,    -41,       30,     -9,       1},
  {1,    -100,    233,     -195,     76,     -14,     1},
  {1,     620,  -1531,     1429,   -659,     161,   -20,     1},
  {1,   -4420,  11537,   -11703,   6110,   -1799,   302,   -27,   1},
  {1,   35900, -98047,   106421, -61174,   20650, -4234,   519, -35,   1},
  {1, -326980, 928529, -1066279, 662506, -248675, 59039, -8931, 835, -44, 1}
		

Crossrefs

Row sums are A040000. Alternating row sums are A058006, which are also T(n,1).
Cf. A186020.

Programs

  • Maple
    with(PolynomialTools):
    T_row := n -> CoefficientList(expand(add(k!*binomial(x, k), k=0..n)), x):
    ListTools:-Flatten([seq(T_row(n), n=0..9)]); # Peter Luschny, Jul 02 2019
  • Mathematica
    p[x_, n_] := Sum[k! Binomial[x, k], {k, 0, n}];
    Table[CoefficientList[FunctionExpand[p[x, n]], x], {n, 0, 10}] // Flatten
    (* Alternative: *)
    Table[CoefficientList[FunctionExpand[Sum[FactorialPower[x, k], {k, 0, n}]], x], {n, 0, 10}] // Flatten (* Peter Luschny, Jul 02 2019 *)

Formula

From Peter Luschny, Jul 02 2019: (Start)
Sum_{k=0..n} T(n, k)*x^k = Sum_{k=0..n} (x)_k, where (x)_k denotes the falling factorial.
Let T be the lower triangular matrix associated to the T(n, k) and S the lower triangular matrix associated to the Stirling set numbers S2(n, k). Then S*T = A186020 (seen as a matrix) and T*S = A000012 (seen as a matrix). (End)
T(n, k) = Sum_{i=0..n-k} Stirling1(i+k, k). - Igor Victorovich Statsenko, May 25 2024

Extensions

Edited by Peter Luschny, Jul 02 2019

A260612 Triangle read by rows: T(n,k) = coefficient of x^(n-k) in Product_{m=0..n-1} (x+(-1)^m*m!), 0 <= k <= n.

Original entry on oeis.org

1, 1, 1, 1, 0, -1, 1, 2, -1, -2, 1, -4, -13, 4, 12, 1, 20, -109, -308, 108, 288, 1, -100, -2509, 12772, 37068, -12672, -34560, 1, 620, -74509, -1793708, 9232908, 26676288, -9158400, -24883200, 1, -4420, -3199309, 373731652, 9049521228, -46507180032, -134457649920, 46133452800, 125411328000
Offset: 0

Views

Author

Matthew Campbell, Aug 08 2015

Keywords

Examples

			Row 0: 1.
Row 1: (x+(-1)^(0)*0!) = x+1. Coefficients are 1 and 1.
Row 2: (x+(-1)^0*0!)*(x+(-1)^(1)*1!) = (x+1)*(x-1) = x^2-1. Coefficients are 1, 0, and -1.
Row 3: (x+(-1)^(0)*0!)*(x-(-1)^(1)*1!)*(x+(-1)^(2)*2!) = (x+1)*(x-1)*(x+2) = x^3 + 2*x^2 - x - 2. Coefficients are 1, 2, -1, and -2.
		

Crossrefs

Formula

T(n, 1) = A058006(n-1) = (-1)^(n+1)*A153229(n) for n >= 1.

A368555 a(n) = Sum_{k=0..n} k! * 3^(n-k).

Original entry on oeis.org

1, 4, 14, 48, 168, 624, 2592, 12816, 78768, 599184, 5426352, 56195856, 647589168, 8169788304, 111687656112, 1642737336336, 25851001897008, 433240433787024, 7702095007089072, 144751385430099216, 2867156164466937648, 59692410665110252944
Offset: 0

Views

Author

Seiichi Manyama, Dec 29 2023

Keywords

Crossrefs

Programs

  • PARI
    a(n) = sum(k=0, n, k!*3^(n-k));

Formula

a(0) = 1; a(n) = 3*a(n-1) + n!.
a(n) = (n+3)*a(n-1) - 3*n*a(n-2).
a(n) ~ n!. - Vaclav Kotesovec, Jan 13 2024

A064493 List of distinct greatest common divisors of { k! and k! - (k-1)! + (k-2)! - ... + (-1)^k*0!, k = 0 .. n}.

Original entry on oeis.org

1, 2, 4, 20, 260, 9620, 4454060
Offset: 0

Views

Author

Vladeta Jovovic, Oct 04 2001

Keywords

Comments

Records in the sequence gcd(k!,A058006(k)). The record indices are products of primes from A064384. There are no further terms unless there are terms in A064384 larger than 463. - Max Alekseyev, Jul 06 2010

Crossrefs

A368573 a(n) = Sum_{k=0..n} k! * k^k.

Original entry on oeis.org

1, 2, 10, 172, 6316, 381316, 33973636, 4184630356, 680641979476, 141267789027796, 36429267789027796, 11425158161234192596, 4282251538636575402196, 1890291840090813125264596, 970616058694975134467523796, 573593232413546537634467523796, 386530943604347679737893326531796
Offset: 0

Views

Author

Seiichi Manyama, Dec 31 2023

Keywords

Crossrefs

Partial sums of A061711.

Programs

  • PARI
    a(n) = sum(k=0, n, k!*k^k);

Formula

a(n) ~ n! * n^n. - Vaclav Kotesovec, Jan 13 2024
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