A339096 Record values in A306400.

5, 7, 11, 23, 701, 3989, 4397, 5501, 7309, 9281, 10331, 11243, 12907, 16127, 27917, 39901, 43051, 44843, 48397, 66569, 70657

Offset

1,1

Links

Table of n, a(n) for n=1..21.

Example

a(3) = 11 is in the sequence because A306400(5) = 11 and A306400(k)<11 for k < 5.

Maple

g:= proc(p) local q;
  q:= 3:
  do
    q:= nextprime(q);
    if isprime(p+q^2-1) and isprime(p+q^2+1) then return q fi;
  od
end proc:
R:= NULL: count:= 0: w:= 0:
for nn from 5 by 6 while count < 15 do
  if isprime(nn) then
    v:= g(nn);
    if v > w then count:= count+1; R:= R, v; w:= v; fi
    fi
od:
R;

Mathematica

g[p_] := Module[{q}, q = 3; While[True, q = NextPrime[q]; If [PrimeQ[p + q^2 - 1] && PrimeQ[p + q^2 + 1], Return@q]]];
R = {}; count = 0; w = 0;
For[nn = 5, count < 15, nn = nn + 6, If[PrimeQ[nn], v = g[nn]; If[v > w, count++; Print[count, " ", v]; R = Append[R, v]; w = v]]];
R (* Jean-François Alcover, Mar 07 2024, after Robert Israel *)

Crossrefs

Cf. A306400.

Sequence in context: A181602 A075705 A340308 * A249735 A218394 A067289

Adjacent sequences: A339093 A339094 A339095 * A339097 A339098 A339099

Keyword

nonn,more

Author

Robert Israel, Nov 23 2020

Extensions

a(16)-a(17) from Jinyuan Wang, Dec 04 2020

a(18)-a(21) from Chai Wah Wu, Jan 15 2021

Status

approved