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A119289
Prime numbers p such that there is no prime between 10*p and 10*p+9 inclusive.
10
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
1,1
COMMENTS
Prime numbers p with property that appending any single decimal digit to p does not produce a prime. Prime members of A032352.
LINKS
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 *)
PROG
(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
CROSSREFS
Supersequence of A239747.
Sequence in context: A251144 A214230 A272367 * A124282 A137869 A096697
KEYWORD
base,nonn
AUTHOR
Tanya Khovanova, Jul 23 2006
EXTENSIONS
More terms sent by several contributors, Jul 23 2006
STATUS
approved