A159236 - OEIS

A159236

Primes that remain prime when a 0 is inserted between every pair of adjacent digits.

11, 13, 17, 19, 37, 41, 53, 59, 61, 67, 71, 79, 89, 97, 107, 109, 113, 131, 151, 167, 179, 193, 199, 211, 257, 277, 293, 313, 337, 359, 373, 383, 389, 409, 457, 479, 577, 599, 613, 617, 659, 661, 673, 691, 701, 709, 727, 739, 751, 757, 827, 829, 839, 863, 883

(list; graph; refs; listen; history; text; internal format)

OFFSET

1,1

COMMENTS

Prime terms in A050674.

See A119680 for the primes obtained by inserting a 0 between each pair of adjacent digits. - Rémy Sigrist, Oct 08 2017

LINKS

Harvey P. Dale, Table of n, a(n) for n = 1..1000

EXAMPLE

409 is prime, and so is 40009 ( 4(0)0(0)9 ). Hence 409 is in the sequence.

MAPLE

Lton := proc(L) add( op(i, L)*10^(i-1), i=1..nops(L)) ; end: pad0 := proc(n) dgs := convert(n, base, 10) ; L := [op(1, dgs)] ; for i from 2 to nops(dgs) do L := [op(L), 0, op(i, dgs)] ; od: Lton(L) ; end: for i from 5 to 400 do p := ithprime(i) ; if isprime( pad0(p) ) then printf("%d, ", p) ; fi; od: # R. J. Mathar, Apr 07 2009

MATHEMATICA

Select[Prime[Range[5, 200]], PrimeQ[FromDigits[Riffle[ IntegerDigits[ #], 0]]]&] (* Harvey P. Dale, Feb 19 2015 *)

PROG

(Python)

from sympy import isprime

def ok(n):

return n > 10 and isprime(n) and isprime(int("0".join(list(str(n)))))

print([k for k in range(900) if ok(k)]) # Michael S. Branicky, Jul 11 2022

CROSSREFS

Cf. A050674, A119680.

Sequence in context: A156902 A050674 A164329 * A215417 A249376 A068155

Adjacent sequences: A159233 A159234 A159235 * A159237 A159238 A159239