cp's OEIS Frontend

A118683 Triangle, T(n,k) = A039701(n) + A039701(k) - A039701(n)*A039701(k), read by rows.

%I A118683 #11 Apr 04 2024 10:16:57
%S A118683 0,2,0,0,2,0,1,1,1,1,0,2,0,1,0,1,1,1,1,1,1,0,2,0,1,0,1,0,1,1,1,1,1,1,
%T A118683 1,1,0,2,0,1,0,1,0,1,0,0,2,0,1,0,1,0,1,0,0,1,1,1,1,1,1,1,1,1,1,1,1,1,
%U A118683 1,1,1,1,1,1,1,1,1,1,0,2,0,1,0,1,0,1,0,0,1,1,0,1,1,1,1,1,1,1,1,1,1,1,1,1,1
%N A118683 Triangle, T(n,k) = A039701(n) + A039701(k) - A039701(n)*A039701(k), read by rows.
%H A118683 G. C. Greubel, <a href="/A118683/b118683.txt">Rows n = 1..50 of the triangle, flattened</a>
%e A118683 Triangle begins as:
%e A118683   0;
%e A118683   2, 0;
%e A118683   0, 2, 0;
%e A118683   1, 1, 1, 1;
%e A118683   0, 2, 0, 1, 0;
%e A118683   1, 1, 1, 1, 1, 1;
%e A118683   0, 2, 0, 1, 0, 1, 0;
%e A118683   1, 1, 1, 1, 1, 1, 1, 1;
%e A118683   0, 2, 0, 1, 0, 1, 0, 1, 0;
%e A118683   0, 2, 0, 1, 0, 1, 0, 1, 0, 0;
%t A118683 A039701[n_]:= Mod[Prime[n],3];
%t A118683 T[n_, k_]:= A039701[n] +A039701[k] -A039701[n]*A039701[k];
%t A118683 Table[T[n,k], {n,12}, {k,n}]//Flatten
%o A118683 (Magma)
%o A118683 A039701:= func< n | NthPrime(n) mod 3 >;
%o A118683 A118683:= func< n,k | A039701(n)+A039701(k)-A039701(n)*A039701(k) >;
%o A118683 [A118683(n,k): k in [1..n], n in [1..12]]; // _G. C. Greubel_, Apr 01 2024
%o A118683 (SageMath)
%o A118683 def A039701(n): return nth_prime(n)%3
%o A118683 def A118683(n,k): return A039701(n)+A039701(k)-A039701(n)*A039701(n)
%o A118683 flatten([[A039701(n,k) for k in range(1,n+1)] for n in range(1,13)]) # _G. C. Greubel_, Apr 01 2024
%Y A118683 Cf. A039701, A099618 (right diagonal).
%K A118683 nonn,tabl,less,easy
%O A118683 1,2
%A A118683 _Roger L. Bagula_, May 19 2006
%E A118683 Offset corrected, definition clarified, sequence extended by Assoc. Eds. of the OEIS, Jun 15 2010