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.
%I A004198 #39 Dec 28 2024 00:07:29 %S A004198 0,0,0,0,1,0,0,0,0,0,0,1,2,1,0,0,0,2,2,0,0,0,1,0,3,0,1,0,0,0,0,0,0,0, %T A004198 0,0,0,1,2,1,4,1,2,1,0,0,0,2,2,4,4,2,2,0,0,0,1,0,3,4,5,4,3,0,1,0,0,0, %U A004198 0,0,4,4,4,4,0,0,0,0,0,1,2,1,0,5,6,5,0,1,2,1,0,0,0,2,2,0,0,6,6,0,0,2,2,0,0,0,1,0 %N A004198 Table of x AND y, where (x,y) = (0,0),(0,1),(1,0),(0,2),(1,1),(2,0),... %C A004198 Or, table of AND(i,j), i >= 0, j >= 0, read by antidiagonals. - _N. J. A. Sloane_, Feb 08 2016 %C A004198 Or, table of (i+j-Nimsum(i,j))/2 read by antidiagonals [Winning Ways, p. 75]. - _N. J. A. Sloane_, Feb 22 2019 %D A004198 E. R. Berlekamp, J. H. Conway and R. K. Guy, Winning Ways, Academic Press, NY, 2 vols., 1982, see p. 75. %H A004198 T. D. Noe, <a href="/A004198/b004198.txt">Rows n=0..100 of triangle, flattened</a> %e A004198 The AND(i,j) table (shown without commas or spaces) begins: %e A004198 0000000000000000000000000... %e A004198 0101010101010101010101010... %e A004198 0022002200220022002200220... %e A004198 0123012301230123012301230... %e A004198 0000444400004444000044440... %e A004198 0101454501014545010145450... %e A004198 0022446600224466002244660... %e A004198 0123456701234567012345670... %e A004198 0000000088888888000000008... %e A004198 0101010189898989010101018... %e A004198 ... %e A004198 The first few antidiagonals are: %e A004198 0, %e A004198 0, 0, %e A004198 0, 1, 0, %e A004198 0, 0, 0, 0, %e A004198 0, 1, 2, 1, 0, %e A004198 0, 0, 2, 2, 0, 0, %e A004198 0, 1, 0, 3, 0, 1, 0, %e A004198 0, 0, 0, 0, 0, 0, 0, 0, %e A004198 0, 1, 2, 1, 4, 1, 2, 1, 0, %e A004198 0, 0, 2, 2, 4, 4, 2, 2, 0, 0, %e A004198 0, 1, 0, 3, 4, 5, 4, 3, 0, 1, 0, %e A004198 ... %e A004198 - _N. J. A. Sloane_, Feb 08 2016 %p A004198 # Maple code for first M rows and columns of AND(i,j) table %p A004198 M:=24; %p A004198 f1:=n->[seq(ANDnos(i,n),i=0..M-1)]; %p A004198 for n from 0 to M-1 do lprint(f1(n)); od: %p A004198 # _N. J. A. Sloane_, Feb 08 2016 %t A004198 Table[BitAnd[k, n - k], {n, 0, 20}, {k, 0, n}] // Flatten (* _Indranil Ghosh_, Apr 01 2017 *) %o A004198 (PARI) %o A004198 tabl(nn) = {for(n=0, nn, for(k=0, n, print1(bitand(k, n - k), ", "); ); print(); ); }; %o A004198 tabl(20) \\ _Indranil Ghosh_, Apr 01 2017 %o A004198 (Python) %o A004198 for n in range(21): %o A004198 print([k&(n - k) for k in range(n + 1)]) %o A004198 # _Indranil Ghosh_, Apr 01 2017 %o A004198 (C) %o A004198 #include <stdio.h> %o A004198 int main() %o A004198 { %o A004198 int n, k; %o A004198 for (n=0; n<=20; n++){ %o A004198 for(k=0; k<=n; k++){ %o A004198 printf("%d, ", (k&(n - k))); %o A004198 } %o A004198 printf("\n"); %o A004198 } %o A004198 return 0; %o A004198 } /* _Indranil Ghosh_, Apr 01 2017 */ %Y A004198 Cf. A003986 (OR) and A003987 (XOR). Cf. also A075173, A075175, A221146. %K A004198 tabl,nonn,look %O A004198 0,13 %A A004198 _David W. Wilson_