A106728 - OEIS

%I #14 Sep 10 2021 03:06:05

%S 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 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 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 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 G. C. Greubel, <a href="/A106728/b106728.txt">Rows n = 0..50 of the triangle, flattened</a>

%F 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 Triangle begins as:

%e   2;

%e   3, 0;

%e   1, 2, 0;

%e   2, 3, 1, 2;

%e   0, 1, 3, 0, 2;

%e   1, 2, 0, 1, 3, 0;

%e   0, 1, 3, 0, 2, 3, 2;

%e   3, 0, 2, 3, 1, 2, 1, 0;

%e   2, 3, 1, 2, 0, 1, 0, 3, 2;

%e   3, 0, 2, 3, 1, 2, 1, 0, 3, 0;

%e   1, 2, 0, 1, 3, 0, 3, 2, 1, 2, 0;

%t f[n_]= 10 -Mod[Prime[n+3], 10];

%t T[n_, k_]:= Mod[Mod[Mod[f[n+1], 5], 4] + Mod[Mod[f[k+1], 5], 4], 4];

%t Table[T[n, k], {n,0,15}, {k,0,n}]//Flatten

%o (Sage)

%o def f(n): return 10 - (nth_prime(n+3)%10)

%o def A106728(n,k): return ( ((f(n+1))%5)%4 + ((f(k+1))%5)%4 )%4

%o flatten([[A106728(n,k) for k in (0..n)] for n in (0..15)]) # _G. C. Greubel_, Sep 10 2021

%Y Cf. A106727.

%K nonn,tabl,easy,less

%O 0,1

%A _Roger L. Bagula_, May 14 2005

%E Edited by _G. C. Greubel_, Sep 10 2021