A176066 - OEIS

%I #16 Jun 28 2024 13:59:27

%S 1,4,2,0,3,0,4,0,4,3,0,1,5,4,0,1,0,1,10,6,5,2,1,2,0,7,6,0,0,4,5,3,10,

%T 9,3,2,1,5,6,4,11,10,4,3,0,3,5,3,0,3,1,11,10,7,6,4,6,4,1,4,2,12,11,8,

%U 7,0,0,0,5,2,5,3,13,12,9,8,1,0,3,3,8,5,8,6,16,15,12,11,4,3,2

%N Triangle read by rows: R(n,k)=semiprime(n+1) mod (semiprime(k)+1), 1<=k<=n.

%F R(n,k) = A001358(n+1) mod (1+A001358(k)).

%e The triangle begins as:

%e   1;

%e   4, 2;

%e   0, 3, 0;

%e   4, 0, 4, 3;

%e   0, 1, 5, 4, 0;

%e   ...

%p A176066 := proc(n,k) A001358(n+1) mod ( A001358(k)+1) ; end proc:

%t Table[Mod[#[[n+1]], #[[;;n]]+1], {n, Length[#]-1}] & [Select[Range[50], PrimeOmega[#] == 2 &]] (* _Paolo Xausa_, Jun 28 2024 *)

%o (PARI) trg(nn) = {semip = select(n->bigomega(n) == 2, vector(nn, i, i)); for (n = 1, #semip-1, for (k = 1, n, print1(semip[n+1] % (semip[k] + 1), ", ");););} \\ _Michel Marcus_, Sep 11 2013

%Y Cf. A000079, A001358, A174996.

%K nonn,tabl

%O 1,2

%A _Juri-Stepan Gerasimov_, Dec 06 2010