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%I #6 Dec 05 2013 19:56:33
%S 2,3,9,11,313,353,363,373,3993,10401,11911,16061,16861,17571,30903,
%T 33633,34043,39693,74347,147741,370073,768867,795597,960069,962269,
%U 1036301,1165611,1405041,1485841,1498941,1601061,1644461,1934391
%N a(1) = 2; then least palindrome greater than the previous term such that every partial concatenation is a prime.
%e 2, 23, 239, 23911, etc., are primes.
%t NextPalindrome[n_] := Block[{l = Floor[ Log[10, n] + 1], idn = IntegerDigits[n]}, If[ Union[idn] == {9}, Return[n + 2], If[l < 2, Return[n + 1], If[ FromDigits[ Reverse[ Take[ idn, Ceiling[l/2]]]] FromDigits[ Take[ idn, -Ceiling[l/2]]], FromDigits[ Join[ Take[ idn, Ceiling[l/2]], Reverse[ Take[ idn, Floor[l/2]]]]], idfhn = FromDigits[ Take[ idn, Ceiling[l/2]]] + 1; idp = FromDigits[ Join[ IntegerDigits[ idfhn], Drop[ Reverse[ IntegerDigits[ idfhn]], Mod[l, 2]]]]]]]]; a = 2; k = 2; f[n_, m_] := Block[{k = NextPalindrome[m]}, While[b = FromDigits[ Join[ IntegerDigits[n], IntegerDigits[k]]]; !PrimeQ[b], k = NextPalindrome[k]]; Return[b]]; f[2, 2]; f[%, 3]; etc.
%Y Cf. A088085, A088086.
%K base,nonn
%O 1,1
%A _Amarnath Murthy_, Sep 22 2003
%E Edited, corrected and extended by _Robert G. Wilson v_, Sep 27 2003
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