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.

A133128 Triangle of first differences of A120070 with a leftmost column of A002522.

Original entry on oeis.org

2, 5, -3, 10, -3, -5, 17, -3, -5, -7, 26, -3, -5, -7, -9, 37, -3, -5, -7, -9, -11, 50, -3, -5, -7, -9, -11, -13, 65, -3, -5, -7, -9, -11, -13, -15, 82, -3, -5, -7, -9, -11, -13, -15, -17, 101, -3, -5, -7, -9, -11, -13, -15, -17, -19, 122, -3, -5, -7, -9, -11, -13, -15, -17, -19, -21, 145, -3, -5, -7, -9, -11, -13, -15, -17, -19, -21, -23, 170, -3, -5, -7, -9, -11, -13
Offset: 0

Views

Author

Paul Curtz, Aug 27 2008

Keywords

Comments

The flattened triangle is essentially the same as A141620.

Examples

			The triangle starts
2;
5, -3;
10,-3,-5;
17,-3,-5,-7;
26,-3,-5,-7,-9;
		

Programs

  • Maple
    A133128 := proc(n,m) if m>= 1 then -2*m-1 ; else (n+1)^2+1 ; fi; end: seq(seq(A133128(n,m),m=0..n),n=0..15) ; # R. J. Mathar, Nov 22 2009

Formula

T(n,0) = A002522(n+1).
T(n,m) = -2m-1, m>0 .
sum_{m=0..n} T(n,m) = 2 (row sums).
T(n,n) = -A005408(n), n>0.

Extensions

Edited and extended by R. J. Mathar, Nov 22 2009