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 A364937 a(n) is the least prime p such that p - prime(n) and p + prime(n) are triprimes. 1
 173, 47, 13, 37, 19, 31, 59, 31, 43, 37, 61, 79, 61, 71, 67, 61, 71, 103, 97, 83, 101, 107, 103, 97, 139, 167, 179, 137, 127, 131, 139, 151, 149, 151, 167, 181, 199, 191, 269, 181, 191, 193, 211, 211, 239, 211, 223, 251, 271, 241, 241, 269, 283, 353, 277, 271, 313, 347, 401, 293, 313, 311, 409 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 LINKS Robert Israel, Table of n, a(n) for n = 1..10000 EXAMPLE a(3) = 13 because prime(3) = 5 and 13 - 5 = 8 = 2^3 and 13 + 5 = 18 = 2*3^2 are triprimes. MAPLE f:= proc(n) local p, q; q:= ithprime(n); p:= q; do p:= nextprime(p); if numtheory:-bigomega(p-q) = 3 and numtheory:-bigomega(p+q) = 3 then return p fi; od end proc; map(f, [\$1..100]); MATHEMATICA s={}; p=1; Do[p=NextPrime[p]; q=NextPrime[p]; While[3!= PrimeOmega[q+p]||3!= PrimeOmega[q-p], q=NextPrime[q]]; AppendTo[s, q], {100}]; CROSSREFS Cf. A014612. Sequence in context: A035828 A259017 A097845 * A261530 A246135 A140002 Adjacent sequences: A364934 A364935 A364936 * A364938 A364939 A364940 KEYWORD nonn AUTHOR Zak Seidov and Robert Israel, Aug 13 2023 STATUS approved

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Last modified June 23 11:52 EDT 2024. Contains 373648 sequences. (Running on oeis4.)