A354590 a(n) is the first prime that is the start of a sequence of exactly n consecutive primes that are in A354589.

11, 47, 251, 9431, 191, 19457, 280627, 2213, 1006253, 9129563, 66945301, 184171621, 726512053, 2732087209, 10206934519, 59883612989, 25650350371

Offset: 1

Author

J. M. Bergot and Robert Israel, Aug 18 2022

Keywords

• nonn
• more
• base

Examples

			a(3) = 251 because the 4 primes starting with 251 are 251, 257, 263, 269, and 251, 257 and 263 are in A354589 but 269 is not; and 251 is the least prime for which this works.
		

Crossrefs

Cf. A007652, A354589.

Programs

Maple

P:= select(isprime, [seq(i,i=1..10^7,2)]):
nP:= nops(P);
P10:= P mod 10:
s:= 0: V:= Vector(10):
for i from 1 to nP-3 do
  if convert(P10[i..i+3],set) = {1,3,7,9} then s:= s+1
  else
    if s > 0 and s <= 10 and V[s] = 0 then V[s]:= P[i-s] fi;
    s:= 0
  fi
od:
convert(V, list);

Extensions

a(11)-a(14) from Michael S. Branicky, Aug 18 2022

a(15)-a(17) from Michael S. Branicky, Aug 20 2022