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.

A080232 Triangle T(n,k) of differences of pairs of consecutive terms of triangle A071919.

This page as a plain text file.
%I A080232 #29 Oct 23 2018 05:49:48
%S A080232 1,1,-1,1,0,-1,1,1,-1,-1,1,2,0,-2,-1,1,3,2,-2,-3,-1,1,4,5,0,-5,-4,-1,
%T A080232 1,5,9,5,-5,-9,-5,-1,1,6,14,14,0,-14,-14,-6,-1,1,7,20,28,14,-14,-28,
%U A080232 -20,-7,-1,1,8,27,48,42,0,-42,-48,-27,-8,-1
%N A080232 Triangle T(n,k) of differences of pairs of consecutive terms of triangle A071919.
%C A080232 Row sums are 1,0,0,0,0,0, ... with g.f. 1 = (1-x)^0(1-2x)^0
%C A080232 (1,-1)-Pascal triangle; mirror image of triangle A112467. - _Philippe Deléham_, Nov 07 2006
%C A080232 Triangle T(n,k), read by rows, given by (1,0,0,0,0,0,0,0,0,...) DELTA (-1,2,0,0,0,0,0,0,0,...) where DELTA is the operator defined in A084938. - _Philippe Deléham_, Nov 01 2011
%H A080232 T. M. Brown, <a href="https://arxiv.org/abs/1810.08235">On the unimodality of convolutions of sequences of binomial coefficients</a>, arXiv:1810.08235 [math.CO] (2018). See p. 8.
%H A080232 Pedro J. Miana, Hideyuki Ohtsuka, Natalia Romero, <a href="http://arxiv.org/abs/1602.04347">Sums of powers of Catalan triangle numbers</a>, arXiv:1602.04347 [math.NT], 2016.
%F A080232 T(n, k) = binomial(n, k) + 2*Sum{j=1...k} (-1)^j binomial(n, k-j).
%F A080232 Sum_{k=0..n} T(n, k)*x^k = (1-x)*(1+x)^(n-1), for n >= 1. - _Philippe Deléham_, Sep 05 2005
%F A080232 T(n,k) = T(n-1,k-1) + T(n-1,k) with T(n,0)=1, T(n,n)=-1 for n > 0. - _Philippe Deléham_, Nov 01 2011
%F A080232 T(n,k)  =binomial(n-1,k) - binomial(n-1,k-1), for n > 0. T(n,k) = Sum_{i=-k..k} (-1)^i*binomial(n-1,k+i)*binomial(n+1,k-i), for n >= k. T(n,k)=0, for n < k. - _Mircea Merca_, Apr 28 2012
%F A080232 G.f.: (-1+2*x*y)/(-1+x*y+x). - _R. J. Mathar_, Aug 11 2015
%e A080232 Rows begin
%e A080232   1;
%e A080232   1,  -1;
%e A080232   1,   0,  -1;
%e A080232   1,   1,  -1,  -1;
%e A080232   1,   2,   0,  -2,  -1;
%e A080232   1,   3,   2,  -2,  -3,  -1;
%e A080232   1,   4,   5,   0,  -5,  -4,  -1;
%e A080232   1,   5,   9,   5,  -5,  -9,  -5,  -1;
%e A080232   1,   6,  14,  14,   0, -14, -14,  -6,  -1;
%e A080232   1,   7,  20,  28,  14, -14, -28, -20,  -7,  -1;
%e A080232   1,   8,  27,  48,  42,   0, -42, -48, -27,  -8,  -1;
%p A080232 T(n,k):=piecewise(n=0,1,n>0,binomial(n-1,k)-binomial(n-1,k-1)) # _Mircea Merca_, Apr 28 2012
%Y A080232 Cf. A007318, A071919.
%Y A080232 Apart from initial term, same as A037012.
%K A080232 easy,sign,tabl
%O A080232 0,12
%A A080232 _Paul Barry_, Feb 09 2003