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 A173662 Triangle read by rows: R(n,k)= semiprime(n) mod semiprime(k), 0
 0, 2, 0, 1, 3, 0, 2, 4, 1, 0, 2, 2, 5, 4, 0, 3, 3, 6, 5, 1, 0, 1, 3, 3, 1, 7, 6, 0, 2, 4, 4, 2, 8, 7, 1, 0, 1, 1, 7, 5, 11, 10, 4, 3, 0, 2, 2, 8, 6, 12, 11, 5, 4, 1, 0, 1, 3, 6, 3, 5, 3, 12, 11, 8, 7, 0, 2, 4, 7, 4 (list; table; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 COMMENTS Row sums are 0, 2, 4, 7, 13, 18, 28,... LINKS EXAMPLE 0, 2,0; 1,3,0; 2,4,1,0; 2,2,5,4,0; 3,3,6,5,1,0; 1,3,3,1,7,6,0; 2,4,4,2,8,7,1,0; MATHEMATICA SemiprimeQ[n_Integer] := If[Abs[n]<2, False, (2==Plus@@Transpose[FactorInteger[Abs[n]]][[2]])]; sp = Select[Range[100], SemiprimeQ]; Flatten[Table[Mod[sp[[n]], sp[[Range[n]]]], {n, Length[sp]}]] CROSSREFS Cf. A001358, A173655. Sequence in context: A219311 A022880 A128097 * A172026 A060318 A089994 Adjacent sequences:  A173659 A173660 A173661 * A173663 A173664 A173665 KEYWORD nonn,tabl,easy AUTHOR Juri-Stepan Gerasimov, Nov 28 2010 EXTENSIONS 46th term corrected by D. S. McNeil, Nov 24 2010 STATUS approved

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