A176066 Triangle read by rows: R(n,k)=semiprime(n+1) mod (semiprime(k)+1), 1<=k<=n.

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, 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, 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

Offset

1,2

Links

Table of n, a(n) for n=1..91.

Formula

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

Example

The triangle begins as:
  1;
  4, 2;
  0, 3, 0;
  4, 0, 4, 3;
  0, 1, 5, 4, 0;
  ...

Maple

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

Mathematica

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

Prog

(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

Crossrefs

Cf. A000079, A001358, A174996.

Sequence in context: A129681 A126079 A106220 * A376742 A309987 A350358

Adjacent sequences: A176063 A176064 A176065 * A176067 A176068 A176069

Keyword

nonn,tabl

Author

Juri-Stepan Gerasimov, Dec 06 2010

Status

approved