NextPrime[ n_Integer ] := Module[ {k = n + 1}, While[ ! PrimeQ[ k ], k++ ]; Return[ k ]]; PrevPrime[ n_Integer ] := Module[ {k = n - 1}, While[ ! PrimeQ[ k ], k-- ]; Return[ k ]]; p = 0; Do[ a = Table[ -1, {n} ]; k = Max[ 1, p ]; While[ Union[ a ] != {7}, k = NextPrime[ k ]; a = Take[ AppendTo[ a, Mod[ k, 8 ]], -n ]]; p = NestList[ PrevPrime, k, n ]; Print[ p[[ -2 ] ]]; p = p[[ -1 ]], {n, 1, 8} ]
With[{pm8=Table[If[Mod[p, 8]==7, 1, 0], {p, Prime[Range[16730000]]}]}, Prime[#]&/@Table[SequencePosition[pm8, PadRight[{}, n, 1], 1], {n, 10}]][[;; , 1, 1]] (* The program generates the first 10 terms of the sequence. *) (*
Harvey P. Dale, Dec 12 2025 *)
