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Palindromic primes with digit sum = 11.
1

%I #6 Nov 06 2015 02:02:05

%S 191,353,13331,1123211,1221221,1303031,1311131,3103013,110232011,

%T 111050111,112030211,112111211,121111121,130030031,301111103,

%U 10000900001,10002520001,10013131001,10111311101,10301110301

%N Palindromic primes with digit sum = 11.

%C Conjecture: The sequence is unbounded.

%H Chai Wah Wu, <a href="/A070831/b070831.txt">Table of n, a(n) for n = 1..2388</a>

%t Do[p = Join[ IntegerDigits[n], Reverse[ Drop[ IntegerDigits[n], -1]]]; q = Plus @@ p; If[ PrimeQ[ FromDigits[p]] && q == 11, Print[ FromDigits[p]]], {n, 1, 10^6}]

%Y Cf. A002385, A070247, A070248 and A070249.

%K base,nonn

%O 1,1

%A _Robert G. Wilson v_, May 15 2002