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 A103397 Semiprimes in A103377. 6
 4, 9, 15, 21, 33, 38, 58, 65, 86, 106, 121, 129, 265, 511, 8114, 8193, 16307, 16853, 17855, 19857, 31298, 68037, 104739, 124205, 131209, 134149, 140457, 152849, 252914, 259918, 265358, 274606, 417527, 2498871, 5291863, 8424051, 8743821 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 LINKS FORMULA Intersection of A103377 with A001358. EXAMPLE 2071468241 is an element of A103377 and 2071468241= 17 * 121851073 which shows that it is a semiprime. MATHEMATICA SemiprimeQ[n_]:=Plus@@FactorInteger[n][[All, 2]]?2; Clear[a]; k=9; Do[a[n]=1, {n, k+1}]; a[n_]:=a[n]=a[n-k]+a[n-k-1]; A103377=Array[a, 100] A103387=Union[Select[Array[a, 1000], PrimeQ]] A103397=Union[Select[Array[a, 300], SemiprimeQ]] N[Solve[x^10 - x - 1 == 0, x], 111][[2]] CROSSREFS Cf. A001358, A000931, A079398, A103372-103381, A103377, A103397. Sequence in context: A103400 A103399 A103398 * A103394 A103395 A103393 Adjacent sequences:  A103394 A103395 A103396 * A103398 A103399 A103400 KEYWORD easy,nonn AUTHOR Jonathan Vos Post, Feb 15 2005 STATUS approved

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