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A177266
Triangle read by rows: R(n,k) = 2^(semiprime(n)-semiprime(k)) mod semiprime(n).
0
1, 4, 1, 5, 8, 1, 4, 6, 2, 1, 2, 4, 4, 2, 1, 8, 2, 4, 2, 2, 1, 11, 8, 1, 11, 2, 1, 1, 14, 20, 8, 4, 14, 18, 2, 1, 2, 13, 11, 18, 23, 24, 16, 8, 1, 10, 22, 6, 16, 14, 20, 6, 16, 2, 1, 17, 29, 16, 8, 17, 25, 4, 2, 25, 29, 1, 30, 16, 2, 18, 16, 8, 32, 16, 2, 18, 2, 1, 23, 32, 4, 2, 22
OFFSET
1,2
EXAMPLE
Triangle begins:
1,
4, 1,
5, 8, 1,
4, 6, 2, 1,
2, 4, 4, 2, 1,
8, 2, 4, 2, 2, 1,
MATHEMATICA
Table[PowerMod[2, #[[n]] - #[[;; n]], #[[n]]], {n, Length[#]}] & [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, for (k = 1, n, print1(2^(semip[n] - semip[k]) % semip[n], ", "); ); print(); ); } \\ Michel Marcus, Sep 11 2013
CROSSREFS
KEYWORD
nonn,tabl
AUTHOR
EXTENSIONS
Corrected by D. S. McNeil, Dec 10 2010
STATUS
approved