OFFSET
1,1
LINKS
Michael S. Branicky, Table of n, a(n) for n = 1..10000
EXAMPLE
227 is a term as the previous prime 223 also has only prime digits.
MATHEMATICA
NextPrim[n_] := Block[{k = n + 1}, While[ !PrimeQ[k], k++ ]; k]; p = 0; q = 1; pd = {1}; Do[p = q; pd = qd; q = NextPrim[p]; qd = Union[ Join[{2, 3, 5, 7}, IntegerDigits[q]]]; If[pd == qd == {2, 3, 5, 7}, Print[q]], {n, 1, 20000}]
Transpose[Select[Partition[Prime[Range[20000]], 2, 1], And@@PrimeQ[ Flatten[ IntegerDigits/@#]]&]] [[2]] (* Harvey P. Dale, Jul 19 2011 *)
PROG
(Python)
from sympy import nextprime, isprime
from itertools import count, islice, product
def onlypd(n): return set(str(n)) <= set("2357")
def agen():
yield from [3, 5, 7]
for digits in count(2):
for p in product("2357", repeat=digits-1):
for end in "37":
t = int("".join(p) + end)
if isprime(t):
t2 = nextprime(t)
if onlypd(t2):
yield t2
print(list(islice(agen(), 40))) # Michael S. Branicky, Mar 11 2022
CROSSREFS
KEYWORD
base,nonn
AUTHOR
Amarnath Murthy, Apr 18 2003
EXTENSIONS
Edited and extended by Robert G. Wilson v, Apr 22 2003
a(38) and beyond from Michael S. Branicky, Mar 11 2022
STATUS
approved