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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A299146 Modified Pascal's triangle read by rows: T(n,k) = C(n+1,k) - n, 1 <= k <= n.

Original entry on oeis.org

1, 1, 1, 1, 3, 1, 1, 6, 6, 1, 1, 10, 15, 10, 1, 1, 15, 29, 29, 15, 1, 1, 21, 49, 63, 49, 21, 1, 1, 28, 76, 118, 118, 76, 28, 1, 1, 36, 111, 201, 243, 201, 111, 36, 1, 1, 45, 155, 320, 452, 452, 320, 155, 45, 1, 1, 55, 209, 484, 781, 913, 781, 484, 209, 55, 1
Offset: 1

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Author

Juri-Stepan Gerasimov, Feb 03 2018

Keywords

Comments

If we define T_m(n, k) = binomial(n+m,k) - m*n where m <= k <= n, then T_0 is Pascal's triangle A007318 and T_1 is the current triangle sequence.
This modified Pascal's triangle is symmetric: C(n+m, k) - m*n = C(n+m, n-k+1) - m*n for any nonnegative integer m.

Examples

			The triangle T(n, k) begins:
n\k  1    2    3    4    5    6    7    8    9   10
1    1;
2    1,   1;
3    1,   3,   1;
4    1,   6,   6,   1;
5    1,  10,  15,  10,   1;
6    1,  15,  29,  29,  15,   1;
7    1,  21,  49,  63,  49,  21,   1;
8    1,  28,  76, 118, 118,  76,  28,   1;
9    1,  36, 111, 201, 243, 201, 111,  36,   1;
10   1,  45, 155, 320, 452, 452, 320, 155,  45,   1; etc.
		

Crossrefs

Programs

  • GAP
    Flat(List([1..100],n->List([1..n],k->Binomial(n+1,k)-n))); # Muniru A Asiru, Feb 05 2018
    
  • Magma
    [[Binomial(n+1, k)- 1*n: k in [1..n]]: n in [1..10]];
    
  • Maple
    seq(seq(binomial(n+1,k)-n, k=1..n), n=1..10); # Muniru A Asiru, Feb 05 2018
  • Mathematica
    Table[Binomial[n + 1, k] - n, {n, 11}, {k, n}] // Flatten (* Michael De Vlieger, Feb 05 2018 *)
  • PARI
    T(n, k) = binomial(n+1,k) - n;
    tabl(nn) = for (n=1, nn, for (k=1, n, print1(T(n, k), ", ")); print); \\ Michel Marcus, Mar 01 2018

Formula

T(n, k) = T_1(n, k) = binomial(n+1, k) - n, for 1 <= k <= n.
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