login
A069676
Primes with either no internal digits or all internal digits are 1.
10
2, 3, 5, 7, 11, 13, 17, 19, 23, 29, 31, 37, 41, 43, 47, 53, 59, 61, 67, 71, 73, 79, 83, 89, 97, 113, 211, 311, 313, 317, 419, 613, 617, 619, 719, 811, 911, 919, 1117, 2111, 2113, 3119, 4111, 5113, 5119, 6113, 8111, 8117, 11113, 11117, 11119, 41113, 41117, 71119
OFFSET
1,1
LINKS
MATHEMATICA
aid1Q[n_]:=Union[Most[Rest[IntegerDigits[n]]]]=={1}; Join[Prime[Range[PrimePi[ 100]]], Select[Prime[Range[PrimePi[100]+1, 7100]], aid1Q]] (* Harvey P. Dale, Apr 12 2013 *)
PROG
(PARI) lista(na) = my(vp = List(primes(primepi(100)))); for (n=1, na, my(x=(10^n-1)/9); for (i=1, 9, forstep(j=1, 9, 2, my(y=10^(n+1)*i + 10*x + j); if (ispseudoprime(y), listput(vp, y)); ); ); ); Vec(vp); \\ Michel Marcus, Jul 12 2022
KEYWORD
nonn,base
AUTHOR
Amarnath Murthy, Apr 06 2002
EXTENSIONS
Corrected by Ray Chandler, Nov 24 2003
Offset corrected and name changed by Arkadiusz Wesolowski, Sep 07 2011
STATUS
approved