A088603 a(n) = smallest prime in which n substrings containing the most significant digit are primes.

2, 23, 233, 2333, 23333, 233993, 2339933, 23399339, 1979339333, 23339531339, 293999994791, 3733799959397, 233323747999733, 2333939994739931, 23833939369399333, 238339393693993337, 23833939369399333613

Offset: 1

Author

Amarnath Murthy, Oct 15 2003

Keywords

• base
• nonn

Comments

Agrees with A127889 for 8 terms, but A127889 ends there while this sequence continues. - Ray Chandler, Mar 13 2007

Crossrefs

Cf. A088604, A127889.

Programs

PARI

f(n, d, spare) = local(p, r); if (!d, return(n)); for (i = 0, 9, p = 10*n + i; if (isprime(p) || spare, r = f(p, d - 1, spare - 1 + isprime(p))); if (r, return(r))); 0;
a(n) = local(i, r); i = 0; while (1, r = f(0, n + i, i); if (r, return(r), i++)); \\ David Wasserman, Aug 12 2005

Extensions

Corrected and extended by David Wasserman, Aug 12 2005