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 A296012 Primes of the form k + k+1 + k+2 +-1 where k, k+1, and k+2 are all composite numbers. 2
 79, 101, 103, 149, 151, 167, 191, 193, 227, 229, 257, 277, 281, 283, 347, 349, 353, 359, 367, 373, 401, 431, 433, 439, 461, 463, 479, 509, 557, 563, 607, 613, 617, 619, 641, 643, 647, 653, 659, 661, 709, 733, 739, 743, 761, 797, 821, 823, 857, 859, 863, 887, 907, 911, 967, 971, 977, 983, 1019, 1021 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS Primes p such that floor((p-2)/3) and floor((p-2)/3)+2 are composite. - Robert Israel, Dec 03 2017 LINKS Chai Wah Wu, Table of n, a(n) for n = 1..10000 EXAMPLE 25 + 26 + 27 + 1 = 79, 33 + 34 + 35 - 1 = 101, 33 + 34 + 35 + 1 = 103, etc. MAPLE filter:= proc(n) local k;   if not isprime(n) then return false fi;   k:= floor((n-2)/3);   not isprime(k) and not isprime(k+1) and not isprime(k+2) end proc: select(filter, [seq(i, i=5..2000, 2)]); # Robert Israel, Dec 03 2017 MATHEMATICA Select[Join @@ Map[{{Total@ # - 1, #}, {Total@ # + 1, #}} &, Partition[Range@ 350, 3, 1]], And[PrimeQ@ First@ #, AllTrue[Last@ #, CompositeQ]] &][[All, 1]] (* Michael De Vlieger, Dec 03 2017 *) PROG (Python) from __future__ import division from sympy import nextprime, isprime A296012_list, p = [], 2 while len(A296012_list) < 10000:     k = (p-2)//3     if not (isprime(k) or isprime(k+2)):         A296012_list.append(p)     p = nextprime(p) # Chai Wah Wu, Jan 24 2018 CROSSREFS Cf. A000045, A136799. Sequence in context: A285228 A087537 A117840 * A193142 A033250 A139922 Adjacent sequences:  A296009 A296010 A296011 * A296013 A296014 A296015 KEYWORD nonn AUTHOR Martin Michael Musatov, Dec 02 2017 STATUS approved

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Last modified September 18 06:40 EDT 2020. Contains 337166 sequences. (Running on oeis4.)