A110743 - OEIS

%I #11 Dec 05 2013 19:57:03

%S 11,2,3,41,5,61,7,83,97,11,11,211,31,41,5101,61,71,811,911,2,127,223,

%T 3203,421,521,6203,727,821,929,3,13,23,331,43,53,631,73,83,937,41,149,

%U 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

%N Smallest prime beginning with n reversed.

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

%o (PARI) okdigs(np, dfp) = {dnp = digits(np); xdnp = vector(#dfp, id, dnp[id]); return (xdnp == dfp);}

%o 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

%Y Cf. A018800, A089356.

%K base,easy,nonn,less

%O 1,1

%A _Amarnath Murthy_, Aug 10 2005

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