login
The OEIS is supported by the many generous donors to the OEIS Foundation.

 

Logo
Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A082755 Smaller of a pair of consecutive primes having only prime digits. 4
2, 3, 5, 223, 727, 3253, 3727, 5233, 5323, 7573, 7723, 7753, 22273, 23327, 25523, 27733, 32233, 32323, 32533, 35323, 35533, 37253, 37273, 52223, 52727, 53323, 53327, 53773, 55333, 72223, 72727, 75223, 75527, 75553, 222527, 222533, 222553, 223273, 223753, 225223 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

Chai Wah Wu, Table of n, a(n) for n = 1..10000 (Terms for n = 1..1000 from Harvey P. Dale)

EXAMPLE

223 is a term as the next prime 227 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[p]], {n, 1, 20000}]

Prime[#]&/@SequencePosition[Table[If[AllTrue[IntegerDigits[n], PrimeQ], 1, 0], {n, Prime[Range[20000]]}], {1, 1}][[All, 1]] (* Requires Mathematica version 10 or later *) (* Harvey P. Dale, Aug 31 2017 *)

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 [2, 3, 5]

    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) and onlypd(nextprime(t)):

                    yield t

print(list(islice(agen(), 40))) # Michael S. Branicky, Mar 11 2022

CROSSREFS

Cf. A019546, A082756.

Sequence in context: A082520 A062597 A038526 * A042067 A333803 A338262

Adjacent sequences:  A082752 A082753 A082754 * A082756 A082757 A082758

KEYWORD

base,nonn

AUTHOR

Amarnath Murthy, Apr 18 2003

EXTENSIONS

Edited and extended by Robert G. Wilson v, Apr 22 2003

STATUS

approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recents
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified August 11 12:12 EDT 2022. Contains 356065 sequences. (Running on oeis4.)