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

1,1

Comments

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

Links

Table of n, a(n) for n=1..17.

Prog

(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

Crossrefs

Cf. A088604, A127889.

Sequence in context: A198972 A065122 A127889 * A048549 A158191 A089703

Adjacent sequences: A088600 A088601 A088602 * A088604 A088605 A088606

Keyword

base,nonn

Author

Amarnath Murthy, Oct 15 2003

Extensions

Corrected and extended by David Wasserman, Aug 12 2005

Status

approved