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.

A140589 Triangle A(k,n) = (-2)^k+2^n read by rows.

Original entry on oeis.org

2, -1, 0, 5, 6, 8, -7, -6, -4, 0, 17, 18, 20, 24, 32, -31, -30, -28, -24, -16, 0, 65, 66, 68, 72, 80, 96, 128, -127, -126, -124, -120, -112, -96, -64, 0, 257, 258, 260, 264, 272, 288, 320, 384, 512, -511, -510, -508, -504, -496, -480, -448, -384, -256, 0, 1025, 1026, 1028, 1032
Offset: 0

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Author

Paul Curtz, Jul 06 2008

Keywords

Comments

The flattened sequence a(A000217(k)+j)=A(k,j) obeys a(n+1)-2a(n)= -5, 2, 5, -4, -4, -23, 8, 8, 8, 17, -16, -16, -16, -16, -95, ..., which is a dispersion of 2, -4, -4, 8, 8, 8, ... (a signed version of A140513) with -5, 5, -23, 17, -95, 65,... The latter sequence is A(k,0)-2*A(k-1,k-1), an alternation of the negative of A140529 with each second element of A000051.

Examples

			Rows starting at k=0: (2), (-1,0); (5, 6, 8); (-7,-6,-4,0); (17,18,20,24,32);...
		

Formula

A(k,n) = A000079(n)+A122803(k).

Extensions

Edited by R. J. Mathar, Jul 08 2008