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 A345224 a(n) is the least prime p such that there are exactly n primes of the form p+2^k for 2^k < p. 1
 61, 2, 11, 67, 149, 2081, 5651, 11831, 51479, 536279, 3058871, 11894801, 106446433 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,1 LINKS FORMULA A345238(A000720(a(n))) = n. EXAMPLE a(3) = 67 because 67+2^2 = 71, 67+2^4 = 83 and 67+2^6 = 131 are primes, and 67 is the least prime that produces exactly 3 primes in this way. MAPLE f:= proc(p) local k;   nops(select(isprime, [seq(p+2^k, k=1..ilog2(p))])) end proc: f(2):= 1 V:= Array(0..11): count:= 0: p:= 1: while count < 12 do   p:= nextprime(p);   v:= f(p);   if V[v] = 0 then V[v]:= p; count:= count+1   fi od: convert(V, list); MATHEMATICA Table[p=1; While[Length@Select[Table[Prime@p+2^k, {k, 0, Floor[Log2@Prime@p]}], PrimeQ]!=n, p++]; Prime@p, {n, 0, 9}] (* Giorgos Kalogeropoulos, Jun 11 2021 *) CROSSREFS Cf. A000720, A345238. Sequence in context: A241601 A132096 A051322 * A198189 A102600 A316918 Adjacent sequences:  A345221 A345222 A345223 * A345225 A345226 A345227 KEYWORD nonn,more AUTHOR J. M. Bergot and Robert Israel, Jun 11 2021 STATUS approved

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Last modified June 30 02:41 EDT 2022. Contains 354913 sequences. (Running on oeis4.)