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.

A332352 Triangle read by rows: T(m,n) = Sum_{-m= n >= 1.

Original entry on oeis.org

0, 0, 0, 2, 4, 16, 4, 8, 28, 48, 6, 12, 44, 76, 120, 8, 16, 60, 104, 164, 224, 10, 20, 80, 140, 224, 308, 424, 12, 24, 100, 176, 284, 392, 540, 688, 14, 28, 124, 220, 356, 492, 680, 868, 1096, 16, 32, 148, 264, 428, 592, 820, 1048, 1324, 1600, 18, 36, 176, 316, 516, 716, 996, 1276, 1616, 1956, 2392
Offset: 1

Views

Author

N. J. A. Sloane, Feb 10 2020

Keywords

Examples

			Triangle begins:
0,
0, 0,
2, 4, 16,
4, 8, 28, 48,
6, 12, 44, 76, 120,
8, 16, 60, 104, 164, 224,
10, 20, 80, 140, 224, 308, 424,
12, 24, 100, 176, 284, 392, 540, 688,
14, 28, 124, 220, 356, 492, 680, 868, 1096,
16, 32, 148, 264, 428, 592, 820, 1048, 1324, 1600,
...
		

Crossrefs

The main diagonal is A331772.

Programs

  • Maple
    VR := proc(m,n,q) local a,i,j; a:=0;
    for i from -m+1 to m-1 do for j from -n+1 to n-1 do
    if gcd(i,j)=q then a:=a+(m-abs(i))*(n-abs(j)); fi; od: od: a; end;
    for m from 1 to 12 do lprint(seq(VR(m,n,2),n=1..m),); od:
  • Mathematica
    A332352[m_,n_]:=Sum[If[GCD[i,j]==2,4(m-i)(n-j),0],{i,2,m-1,2},{j,2,n-1,2}]+If[n>2,2(m*n-2m),0]+If[m>2,2(m*n-2n),0];Table[A332352[m, n],{m,15},{n, m}] (* Paolo Xausa, Oct 18 2023 *)