A332352 Triangle read by rows: T(m,n) = Sum_{-m= n >= 1.
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
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, ...
Links
- Paolo Xausa, Table of n, a(n) for n = 1..11325 (rows 1..150 of the triangle, flattened)
- M. A. Alekseyev, M. Basova, and N. Yu. Zolotykh. On the minimal teaching sets of two-dimensional threshold functions. SIAM Journal on Discrete Mathematics 29:1 (2015), 157-165. doi:10.1137/140978090. This sequence is f_2(m,n).
Programs
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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:
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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 *)