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 A003986 #38 Jan 17 2023 09:58:05 %S A003986 0,1,1,2,1,2,3,3,3,3,4,3,2,3,4,5,5,3,3,5,5,6,5,6,3,6,5,6,7,7,7,7,7,7, %T A003986 7,7,8,7,6,7,4,7,6,7,8,9,9,7,7,5,5,7,7,9,9,10,9,10,7,6,5,6,7,10,9,10, %U A003986 11,11,11,11,7,7,7,7,11,11,11,11,12,11,10,11,12,7,6,7,12,11,10,11,12,13,13,11 %N A003986 Table T(n,k) = n OR k read by antidiagonals. %H A003986 T. D. Noe, <a href="/A003986/b003986.txt">Rows n=0..100 of triangle, flattened</a> %F A003986 T(x,y) = T(y,x) = A080098(x,y). - _R. J. Mathar_, May 28 2011 %e A003986 The upper left corner of the array starts in row x=0 with columns y>=0 as: %e A003986 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, ... %e A003986 1, 1, 3, 3, 5, 5, 7, 7, 9, 9, 11, 11, 13, ... %e A003986 2, 3, 2, 3, 6, 7, 6, 7, 10, 11, 10, 11, 14, ... %e A003986 3, 3, 3, 3, 7, 7, 7, 7, 11, 11, 11, 11, 15, ... %e A003986 4, 5, 6, 7, 4, 5, 6, 7, 12, 13, 14, 15, 12, ... %e A003986 5, 5, 7, 7, 5, 5, 7, 7, 13, 13, 15, 15, 13, ... %e A003986 6, 7, 6, 7, 6, 7, 6, 7, 14, 15, 14, 15, 14, ... %e A003986 7, 7, 7, 7, 7, 7, 7, 7, 15, 15, 15, 15, 15, ... %e A003986 8, 9, 10, 11, 12, 13, 14, 15, 8, 9, 10, 11, 12, ... %e A003986 9, 9, 11, 11, 13, 13, 15, 15, 9, 9, 11, 11, 13, ... %e A003986 10, 11, 10, 11, 14, 15, 14, 15, 10, 11, 10, 11, 14, ... %p A003986 read("transforms") ; %p A003986 A003986 := proc(x,y) ORnos(x,y) ;end proc: %p A003986 for d from 0 to 12 do for x from 0 to d do printf("%d,", A003986(x,d-x)) ; end do: end do: # _R. J. Mathar_, May 28 2011 %t A003986 Table[BitOr[k, n - k], {n, 0, 20}, {k, 0, n}] //Flatten (* _Indranil Ghosh_, Apr 01 2017 *) %o A003986 (Haskell) %o A003986 import Data.Bits ((.|.)) %o A003986 a003986 n k = (n - k) .|. k :: Int %o A003986 a003986_row n = map (a003986 n) [0..n] %o A003986 a003986_tabl = map a003986_row [0..] %o A003986 -- _Reinhard Zumkeller_, Aug 05 2014 %o A003986 (PARI) %o A003986 tabl(nn) = {for(n=0, nn, for(k=0, n, print1(bitor(k, n - k), ", "); ); print(); ); }; %o A003986 tabl(20) \\ _Indranil Ghosh_, Apr 01 2017 %o A003986 (Python) %o A003986 for n in range(21): %o A003986 print([k|(n - k) for k in range(n + 1)]) %o A003986 # _Indranil Ghosh_, Apr 01 2017 %o A003986 (C) %o A003986 #include <stdio.h> %o A003986 int main() %o A003986 { %o A003986 int n, k; %o A003986 for (n=0; n<=20; n++){ %o A003986 for(k=0; k<=n; k++){ %o A003986 printf("%d, ", (k|(n - k))); %o A003986 } %o A003986 printf("\n"); %o A003986 } %o A003986 return 0; %o A003986 } /* _Indranil Ghosh_, Apr 01 2017 */ %Y A003986 Cf. A003987 (XOR) and A004198 (AND). Cf. also A075173, A075175. %Y A003986 Antidiagonal sums are in A006583. %K A003986 tabl,nonn,look %O A003986 0,4 %A A003986 _Marc LeBrun_ %E A003986 Name edited by _Michel Marcus_, Jan 17 2023