A110743 Smallest prime beginning with n reversed.

11, 2, 3, 41, 5, 61, 7, 83, 97, 11, 11, 211, 31, 41, 5101, 61, 71, 811, 911, 2, 127, 223, 3203, 421, 521, 6203, 727, 821, 929, 3, 13, 23, 331, 43, 53, 631, 73, 83, 937, 41, 149, 241, 347, 443, 541, 641, 743, 8419, 941, 5, 151, 251, 353, 457, 557, 653, 751, 853, 953, 61, 163, 263, 367, 461, 563, 661, 761, 863, 967

Offset: 1

Author

Amarnath Murthy, Aug 10 2005

Keywords

• base
• easy
• nonn
• less

Examples

			a(10) = least prime beginning with 01, i.e. with 1, which is 11.
		

Crossrefs

Cf. A018800, A089356.

Programs

PARI

okdigs(np, dfp) = {dnp = digits(np); xdnp = vector(#dfp, id, dnp[id]); return (xdnp == dfp);}
a(n) = {revn = subst(Polrev(digits(n), x), x, 10); dn = digits(revn); if (revn == 1, p = 2, p = precprime(revn)); while(! okdigs(p, dn), p = nextprime(p+1);); p;} \\ Michel Marcus, Sep 16 2013

Extensions

More terms from Peter Soung (soung3(AT)hotmail.com), Mar 06 2006