cp's OEIS Frontend

A106728 Triangle T(n, k) = ( ((f(n+1) mod 5) mod 4) + ((f(k+1) mod 5) mod 4) ) mod 4, where f(n) = 10 - (prime(n+3) mod 10).

%I A106728 #14 Sep 10 2021 03:06:05
%S A106728 2,3,0,1,2,0,2,3,1,2,0,1,3,0,2,1,2,0,1,3,0,0,1,3,0,2,3,2,3,0,2,3,1,2,
%T A106728 1,0,2,3,1,2,0,1,0,3,2,3,0,2,3,1,2,1,0,3,0,1,2,0,1,3,0,3,2,1,2,0,2,3,
%U A106728 1,2,0,1,0,3,2,3,1,2,1,2,0,1,3,0,3,2,1,2,0,1,0,0,1,3,0,2,3,2,1,0,1,3,0,3,2
%N A106728 Triangle T(n, k) = ( ((f(n+1) mod 5) mod 4) + ((f(k+1) mod 5) mod 4) ) mod 4, where  f(n) = 10 - (prime(n+3) mod 10).
%H A106728 G. C. Greubel, <a href="/A106728/b106728.txt">Rows n = 0..50 of the triangle, flattened</a>
%F A106728 T(n, k) = ( ((f(n+1) mod 5) mod 4) + ((f(k+1) mod 5) mod 4) ) mod 4, where  f(n) = 10 - (prime(n+3) mod 10).
%e A106728 Triangle begins as:
%e A106728   2;
%e A106728   3, 0;
%e A106728   1, 2, 0;
%e A106728   2, 3, 1, 2;
%e A106728   0, 1, 3, 0, 2;
%e A106728   1, 2, 0, 1, 3, 0;
%e A106728   0, 1, 3, 0, 2, 3, 2;
%e A106728   3, 0, 2, 3, 1, 2, 1, 0;
%e A106728   2, 3, 1, 2, 0, 1, 0, 3, 2;
%e A106728   3, 0, 2, 3, 1, 2, 1, 0, 3, 0;
%e A106728   1, 2, 0, 1, 3, 0, 3, 2, 1, 2, 0;
%t A106728 f[n_]= 10 -Mod[Prime[n+3], 10];
%t A106728 T[n_, k_]:= Mod[Mod[Mod[f[n+1], 5], 4] + Mod[Mod[f[k+1], 5], 4], 4];
%t A106728 Table[T[n, k], {n,0,15}, {k,0,n}]//Flatten
%o A106728 (Sage)
%o A106728 def f(n): return 10 - (nth_prime(n+3)%10)
%o A106728 def A106728(n,k): return ( ((f(n+1))%5)%4 + ((f(k+1))%5)%4 )%4
%o A106728 flatten([[A106728(n,k) for k in (0..n)] for n in (0..15)]) # _G. C. Greubel_, Sep 10 2021
%Y A106728 Cf. A106727.
%K A106728 nonn,tabl,easy,less
%O A106728 0,1
%A A106728 _Roger L. Bagula_, May 14 2005
%E A106728 Edited by _G. C. Greubel_, Sep 10 2021