A126708 - OEIS

%I #8 Sep 24 2013 09:24:39

%S 93871,100043,159389,161071,236627,240551,297233,325693,409499,456623,

%T 468551,524287,550061,583981,614683,617401,653491,705277,722807,

%U 800171,968239,1016839,1040311,1129013,1172261,1276039,1317259,1326277,1379519

%N Prime numbers that are the sum of the cubes of three distinct primes with the same final digit.

%H Harvey P. Dale, <a href="/A126708/b126708.txt">Table of n, a(n) for n = 1..1000</a>

%e 93871 = 13^3 + 23^3 + 43^3 = 2197 + 12167 + 79507 is prime and 13, 23, 43 are primes with the same final digit, hence 93871 is a term.

%e 617401 = 43^3 + 53^3 + 73^3 = 79507 + 148877 + 389017 is prime and 43, 53, 73 are primes with the same final digit, hence 617401 is a term.

%e 14391 = 3^3 + 13^3 + 23^3 = 27 + 2197 + 12167 is not prime; although 3, 13, 23 are primes with the same final digit, 14391 is not in the sequence.

%o (PARI) {m=116; p=m^3; w=[]; forprime(i=1, m-2, r=i%10; forprime(j=i+1, m-1, forprime(k=j+1, m, if(j%10==r&&k%10==r&&(n=i^3+j^3+k^3)<p&&isprime(n), w=concat(w, n))))); w=vecsort(w); for(j=1, #w-1, print1(w[j], ","))} /* Klaus Brockhaus, Feb 16 2007 */

%Y Cf. A125516, A126657, A126658.

%K nonn,base

%O 1,1

%A _Tomas Xordan_, Feb 11 2007

%E Edited, corrected and extended by _Klaus Brockhaus_, Feb 16 2007