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.

A156050 Triangle T(n,m) = binomial(n,m)+2*P(n,m) read by rows, where P(n,m) = 1+A000041(n)-A000041(m)-A000041(n-m).

Original entry on oeis.org

1, 1, 1, 1, 4, 1, 1, 5, 5, 1, 1, 8, 10, 8, 1, 1, 9, 16, 16, 9, 1, 1, 14, 25, 32, 25, 14, 1, 1, 15, 35, 51, 51, 35, 15, 1, 1, 22, 48, 82, 96, 82, 48, 22, 1, 1, 25, 64, 118, 164, 164, 118, 64, 25, 1, 1, 34, 83, 170, 264, 310, 264, 170, 83, 34, 1
Offset: 0

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Author

Roger L. Bagula, Feb 02 2009

Keywords

Comments

The element-by-element sum of: the Pascal triangle A007318 plus two times the elements of P(n,m).
Row sums are 2^n+2*( (n+1)*(1+A000041(n)) -2*A000070(n) ), starting 1, 2, 6, 12, 28, 52, 112, 204, 402, 744, 1414,..., always below factorial(n+1).
The remarkable thing about this sub-Eulerian numbers triangle is that it a Sierpinski gasket modulo 2.

Examples

			P(n,m) starts in row n= 0 as
0
0, 0
0, 1, 0
0, 1, 1, 0
0, 2, 2, 2, 0
0, 2, 3, 3, 2, 0
0, 4, 5, 6, 5, 4, 0
0, 4, 7, 8, 8, 7, 4, 0
0, 7, 10, 13, 13, 13, 10, 7, 0
0, 8, 14, 17, 19, 19, 17, 14, 8, 0
0, 12, 19, 25, 27, 29, 27, 25, 19, 12, 0
to yield T(n,m) from row n=0 on:
1,
1, 1,
1, 4, 1,
1, 5, 5, 1,
1, 8, 10, 8, 1,
1, 9, 16, 16, 9, 1,
1, 14, 25, 32, 25, 14, 1,
1, 15, 35, 51, 51, 35, 15, 1,
1, 22, 48, 82, 96, 82, 48, 22, 1,
1, 25, 64, 118, 164, 164, 118, 64, 25, 1,
1, 34, 83, 170, 264, 310, 264, 170, 83, 34, 1
		

Programs

  • Mathematica
    Clear[f];
    t[n_, m_] = 1 + PartitionsP[n] - PartitionsP[m] - PartitionsP[n - m]; \! Table[(Table[t[n, m], {m, 0, n}] + Reverse[Table[t[n, m], {m, 0, n}]])/2, {n, 0, 10}];
    Table[Table[Binomial[n, m], {m, 0, n}] + (Table[t[n, m], {m, 0, n}] + Reverse[Table[t[n, m], {m, 0, n}]]), {n, 0, 10}];
    Flatten[%]

Extensions

Row sum formula and P(n,m) examples added - The Assoc. Eds. of the OEIS, Aug 29 2010