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 A338373 Numbers k such that bigomega(2*k + 1) >= 4. 1
 40, 67, 94, 112, 121, 148, 157, 175, 187, 202, 220, 229, 247, 256, 262, 283, 292, 310, 312, 337, 346, 364, 367, 382, 391, 409, 412, 418, 427, 437, 445, 472, 487, 499, 514, 517, 526, 535, 544, 553, 562, 577, 580, 598, 607, 612, 634, 637, 643, 652 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS Numbers of the form k + A336263(m) + 2*k*A336263(m) where k and m are positive integers. If a term d in A336263 is not here, bigomega(2*d + 1) = 3. LINKS Dumitru Damian, Table of n, a(n) for n = 1..30000 EXAMPLE 13 is in A336263, therefore 1 + 13 + 2*13*1 = 40 is a term, and (40*2) + 1 = 81 is not the product of 3 prime numbers. MATHEMATICA Select[Range[650], PrimeOmega[2*# + 1] >= 4 &] (* Amiram Eldar, Oct 24 2020 *) PROG (PARI) isok(k) = bigomega(2*k+1) >= 4; \\ Michel Marcus, Oct 24 2020 CROSSREFS Cf. A001222, A336263, A159919. Sequence in context: A204747 A205066 A232870 * A355778 A235283 A134216 Adjacent sequences: A338370 A338371 A338372 * A338374 A338375 A338376 KEYWORD nonn AUTHOR Davide Rotondo, Oct 23 2020 STATUS approved

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Last modified September 22 01:06 EDT 2023. Contains 365503 sequences. (Running on oeis4.)