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.

Showing 1-3 of 3 results.

A275901 Following the successive antidiagonals in A275895, let the n-th queen appear in square (x(n),y(n)); sequence gives x(n).

Original entry on oeis.org

0, 1, 3, 2, 4, 5, 9, 6, 10, 12, 7, 8, 14, 11, 19, 20, 13, 15, 25, 16, 26, 28, 17, 18, 30, 33, 21, 22, 37, 23, 39, 24, 42, 41, 27, 29, 48, 49, 31, 32, 53, 55, 34, 35, 58, 57, 36, 38, 63, 40, 66, 68, 43, 70, 44, 45, 74, 46, 76, 47, 77, 79, 50, 51, 84, 52, 85, 54, 89, 90, 56, 94, 59, 60, 98, 61, 100, 62
Offset: 0

Views

Author

N. J. A. Sloane, Aug 24 2016

Keywords

Comments

See A275902 for y(n).
This is a permutation of the nonnegative numbers.
This assumes the indexing starts at 0. See A275899, A275900 if the indexing begins at 1.

Links

Crossrefs

Cf. A065188, A275895, A275899, A275900, A275902.

Programs

  • Maple
    See A275899.
# Alternative Maple program from N. J. A. Sloane, Oct 03 2016
# To get 10000 terms of A275902 (xx), A275901 (yy), A276783 (ss), -A276325 (dd)
M1:=100000; M2:=22000; M3:=10000;
xx:=Array(0..M1,0); yy:=Array(0..M1,0); ss:=Array(0..M1,0); dd:=Array(0..M1,0);
xx[0]:=0; yy[0]:=0; ss[0]:=0; dd[0]:=0;
for n from 1 to M2 do
sw:=-1;
   for s from ss[n-1]+1 to M2 do
      for i from 0 to s do
         x:=s-i; y:=i;
         if not member(x,xx,'p') and
            not member(y,yy,'p') and
            not member(x-y,dd,'p') then sw:=1; break; fi;
      od:  # od i
if sw=1 then break; fi;
   od: # od s
  if sw=-1 then lprint("error, n=",n); break; fi;
xx[n]:=x; yy[n]:=y; ss[n]:=x+y; dd[n]:=x-y;
od: # od n
[seq(xx[i],i=0..M3)]:
[seq(yy[i],i=0..M3)]:
[seq(ss[i],i=0..M3)]:
[seq(dd[i],i=0..M3)]:

A275902 Following the successive antidiagonals in A275895, let the n-th queen appear in square (x(n),y(n)); sequence gives y(n).

Original entry on oeis.org

0, 2, 1, 4, 3, 8, 5, 10, 7, 6, 12, 14, 9, 18, 11, 13, 21, 24, 15, 26, 17, 16, 28, 30, 19, 20, 34, 36, 22, 38, 23, 40, 25, 27, 44, 47, 29, 31, 50, 52, 32, 33, 55, 57, 35, 37, 59, 62, 39, 65, 41, 42, 69, 43, 71, 73, 45, 75, 46, 77, 49, 48, 81, 83, 51, 85, 53, 88, 54, 56, 91, 58, 95, 97, 60, 99, 61, 101
Offset: 0

Views

Author

N. J. A. Sloane, Aug 24 2016

Keywords

Comments

See A275901 for x(n).
This is a permutation of the nonnegative numbers.
This assumes the indexing starts at 0. See A275899, A275900 if the indexing begins at 1.

Links

Crossrefs

Cf. A065188, A275895, A275899, A275900, A275901.

Programs

  • Maple
    See A275899.
# Alternative Maple program from N. J. A. Sloane, Oct 03 2016
# To get 10000 terms of A275902 (xx), A275901 (yy), A276783 (ss), -A276325 (dd)
M1:=100000; M2:=22000; M3:=10000;
xx:=Array(0..M1,0); yy:=Array(0..M1,0); ss:=Array(0..M1,0); dd:=Array(0..M1,0);
xx[0]:=0; yy[0]:=0; ss[0]:=0; dd[0]:=0;
for n from 1 to M2 do
sw:=-1;
   for s from ss[n-1]+1 to M2 do
      for i from 0 to s do
         x:=s-i; y:=i;
         if not member(x,xx,'p') and
            not member(y,yy,'p') and
            not member(x-y,dd,'p') then sw:=1; break; fi;
      od:  # od i
if sw=1 then break; fi;
   od: # od s
  if sw=-1 then lprint("error, n=",n); break; fi;
xx[n]:=x; yy[n]:=y; ss[n]:=x+y; dd[n]:=x-y;
od: # od n
[seq(xx[i],i=0..M3)]:
[seq(yy[i],i=0..M3)]:
[seq(ss[i],i=0..M3)]:
[seq(dd[i],i=0..M3)]:

A275900 Following the successive antidiagonals in A065188, let the n-th queen appear in square (x(n),y(n)); sequence gives y(n).

Original entry on oeis.org

1, 3, 2, 5, 4, 9, 6, 11, 8, 7, 13, 15, 10, 19, 12, 14, 22, 25, 16, 27, 18, 17, 29, 31, 20, 21, 35, 37, 23, 39, 24, 41, 26, 28, 45, 48, 30, 32, 51, 53, 33, 34, 56, 58, 36, 38, 60, 63, 40, 66, 42, 43, 70, 44, 72, 74, 46, 76, 47, 78, 50, 49, 82, 84, 52, 86, 54, 89, 55, 57, 92, 59, 96, 98, 61, 100, 62, 102
Offset: 1

Views

Author

N. J. A. Sloane, Aug 24 2016

Keywords

Comments

See A275899 for x(n).
This is a permutation of the natural numbers.
This assumes the indexing starts at 1. See A275901, A275902 if the indexing begins at 0.

Links

Crossrefs

Cf. A065188, A275899, A275901, A275902.

Programs

Showing 1-3 of 3 results.

Started in 1964 by Neil J. A. Sloane | Maintained by The OEIS Foundation Inc.

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