A276783 a(n) = A275901(n) + A275902(n).

0, 3, 4, 6, 7, 13, 14, 16, 17, 18, 19, 22, 23, 29, 30, 33, 34, 39, 40, 42, 43, 44, 45, 48, 49, 53, 55, 58, 59, 61, 62, 64, 67, 68, 71, 76, 77, 80, 81, 84, 85, 88, 89, 92, 93, 94, 95, 100, 102, 105, 107, 110, 112, 113, 115, 118, 119, 121, 122, 124, 126, 127, 131, 134, 135, 137, 138, 142, 143, 146, 147, 152, 154, 157, 158, 160, 161, 163, 165, 166, 168, 171

Offset

0,2

Comments

Specifies which diagonals the queens in A275901 and A275902 lie on.

Links

Table of n, a(n) for n=0..81.

Maple

# 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)]:

Crossrefs

Cf A275901, A275902, A276325.

Equals A276324 - 1.

Sequence in context: A281828 A002982 A290432 * A288731 A326422 A093707

Adjacent sequences: A276780 A276781 A276782 * A276784 A276785 A276786

Keyword

nonn

Author

N. J. A. Sloane, Oct 03 2016

Status

approved