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.

A253382 Triangle read by rows: T(n,k) appears in the transformation Sum_{k=0..n} (k+1)*x^k = Sum_{k=0..n} T(n,k)*(x-2k)^k.

Original entry on oeis.org

1, 5, 2, 5, 26, 3, 5, 170, 75, 4, 5, 810, 1035, 164, 5, 5, 3210, 10635, 3764, 305, 6, 5, 11274, 91275, 64244, 10385, 510, 7, 5, 36362, 693387, 910964, 261265, 24030, 791, 8, 5, 110090, 4822155, 11361908, 5422225, 830430, 49175, 1160, 9, 5, 317450, 31364235, 128935028, 98319505, 23510430, 2226455, 91880, 1629, 10
Offset: 0

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Author

Derek Orr, Dec 30 2014

Keywords

Comments

Consider the transformation 1 + 2x + 3x^2 + 4x^3 + ... + (n+1)*x^n = T(n,0)*(x-0)^0 + T(n,1)*(x-2)^1 + T(n,2)*(x-4)^2 + ... + T(n,n)*(x-2n)^n, for n >= 0.

Examples

			From _Wolfdieter Lang_, Jan 14 2015: (Start)
The triangle T(n,k) starts:
n\k 0      1        2         3        4        5       6     7    8  9 ...
0:  1
1:  5
2:  5     26        3
3:  5    170       75         4
4:  5    810     1035       164        5
5:  5   3210    10635      3764      305        6
6:  5  11274    91275     64244    10385      510       7
7:  5  36362   693387    910964   261265    24030     791     8
8:  5 110090  4822155  11361908  5422225   830430   49175  1160    9
9:  5 317450 31364235 128935028 98319505 23510430 2226455 91880 1629 10
... Reformatted.
----------------------------------------------------------------------------
n = 3: 1 + 2*x + 3*x^2 + 4*x^3 = 5*(x-0)^0 +  170*(x-2)^1 + 75*(x-4)^2 + 4*(x-6)^3. (End)
		

Crossrefs

Programs

  • PARI
    T(n, k)=(k+1)-sum(i=k+1, n, (-2*i)^(i-k)*binomial(i, k)*T(n, i))
    for(n=0, 10, for(k=0, n, print1(T(n, k), ", ")))

Formula

T(n,n) = n+1, n >= 0.
T(n,n-1) = n + 2*n^2 + 2*n^3 = A046395(n), for n >= 1.
T(n,n-2) = (n-1)*(2*n^4-2*n^3-2*n^2-2*n+1), for n >= 2.
T(n,n-3) = (n-2)*(4*n^6-24*n^5+38*n^4-6*n^3+12*n^2-36*n+15)/3, for n >= 3.

Extensions

Edited. - Wolfdieter Lang, Jan 14 2015