A119289 Prime numbers p such that there is no prime between 10*p and 10*p+9 inclusive.

53, 89, 107, 113, 167, 179, 251, 317, 347, 389, 397, 419, 431, 443, 457, 461, 521, 599, 641, 643, 653, 709, 727, 761, 773, 797, 839, 863, 887, 907, 911, 977, 991, 1087, 1091, 1103, 1153, 1187, 1213, 1217, 1229, 1231, 1259, 1277, 1283, 1301, 1307, 1319, 1327

Offset: 1

Author

Tanya Khovanova, Jul 23 2006

Keywords

• base
• nonn

Comments

Prime numbers p with property that appending any single decimal digit to p does not produce a prime. Prime members of A032352.

Links

• Michael S. Branicky, Table of n, a(n) for n = 1..10000

Crossrefs

Supersequence of A239747.

Programs

Maple

a:=proc(n) if isprime(n) = true and isprime(10*n+1)=false and isprime(10*n+3)=false and isprime(10*n+5)=false and isprime(10*n+7)=false and isprime(10*n+9)=false then n else fi end: seq(a(n),n=1..1500); # Emeric Deutsch, Jul 24 2006

Mathematica

Select[Prime[Range[1000]], PrimePi[10# + 9] - PrimePi[10# ] == 0 &] (* Stefan Steinerberger, Jul 24 2006 *)

PARI

lista(nn) = {forprime(p=2, nn, if (primepi(10*p+9) - primepi(10*p) == 0, print1(p, ", ")););} \\ Michel Marcus, Jun 23 2015

Python

from sympy import isprime, primerange
def ok(p): s = str(p); return all(not isprime(int(s+d)) for d in "1379")
print(list(filter(ok, primerange(1, 1328)))) # Michael S. Branicky, Aug 08 2021

Extensions

More terms sent by several contributors, Jul 23 2006