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.

A099900 XOR difference triangle, read by rows, of A099901 (in leftmost column) such that the main diagonal equals A099901 shift left and divided by 2.

This page as a plain text file.
%I A099900 #11 Jun 13 2017 22:13:08
%S A099900 1,2,3,6,4,7,14,8,12,11,22,24,16,28,23,46,56,32,48,44,59,118,88,96,64,
%T A099900 112,92,103,206,184,224,128,192,176,236,139,278,472,352,384,256,448,
%U A099900 368,412,279,558,824,736,896,512,768,704,944,556,827,1654,1112,1888,1408
%N A099900 XOR difference triangle, read by rows, of A099901 (in leftmost column) such that the main diagonal equals A099901 shift left and divided by 2.
%C A099900 Central terms of rows equal powers of 2: T(n,[n/2]) = 2^n for n>=0. The leftmost column is A099901. The diagonal forms A099902 and equals the XOR BINOMIAL transform of A099901.
%F A099900 T(n, [n/2]) = 2^n. T(n+1, 0) = 2*T(n, n) (n>=0); T(0, 0)=1; T(n, k) = T(n, k-1) XOR T(n-1, k-1) for n>k>0. T(n, k) = SumXOR_{i=0..k} (C(k, i)mod 2)*T(n-i, 0), where SumXOR is the analog of summation under the binary XOR operation and C(k, i)mod 2 = A047999(k, i).
%e A099900 Rows begin:
%e A099900 [_1],
%e A099900 [_2,3],
%e A099900 [6,_4,7],
%e A099900 [14,_8,12,11],
%e A099900 [22,24,_16,28,23],
%e A099900 [46,56,_32,48,44,59],
%e A099900 [118,88,96,_64,112,92,103],
%e A099900 [206,184,224,_128,192,176,236,139],
%e A099900 [278,472,352,384,_256,448,368,412,279],
%e A099900 [558,824,736,896,_512,768,704,944,556,827],
%e A099900 [1654,1112,1888,1408,1536,_1024,1792,1472,1648,1116,1895],...
%e A099900 notice that the column terms equal twice the diagonal (with offset), and that the central terms in the rows form the powers of 2.
%o A099900 (PARI) T(n,k)=if(n<k || k<0,0,if(k==0,if(n==0,1,2*T(n-1,n-1)), bitxor(T(n,k-1),T(n-1,k-1)));)
%Y A099900 Cf. A099884, A099901, A099902.
%K A099900 eigen,nonn,tabl
%O A099900 0,2
%A A099900 _Paul D. Hanna_, Oct 29 2004