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A132235
Primes congruent to 23 (mod 30).
13
23, 53, 83, 113, 173, 233, 263, 293, 353, 383, 443, 503, 563, 593, 653, 683, 743, 773, 863, 953, 983, 1013, 1103, 1163, 1193, 1223, 1283, 1373, 1433, 1493, 1523, 1553, 1583, 1613, 1733, 1823, 1913, 1973, 2003, 2063, 2153, 2213, 2243, 2273, 2333, 2393
OFFSET
1,1
COMMENTS
Primes (excluding 3) ending in 3 with (SOD-1)/3 non-integer where SOD is sum of digits. - Ki Punches
The sequence is infinite by Dirichlet's theorem. - Arkadiusz Wesolowski, Apr 02 2014
Terms are non-twin primes A007510. - Omar E. Pol, Jul 25 2019
FORMULA
a(n) = A158791(n)*30 + 23. - Ray Chandler, Apr 07 2009
Intersection of A030431 and A007528. - Ray Chandler, Apr 07 2009
MATHEMATICA
Select[Prime[Range[1000]], MemberQ[{23}, Mod[#, 30]]&] (* Vincenzo Librandi, Aug 14 2012 *)
Select[Range[23, 2400, 30], PrimeQ] (* Harvey P. Dale, Jan 27 2020 *)
PROG
(Magma) [p: p in PrimesUpTo(3000) | p mod 30 eq 23 ]; // Vincenzo Librandi, Aug 14 2012
(PARI) is(n)=isprime(n) && n%30==23 \\ Charles R Greathouse IV, Jul 01 2016
KEYWORD
nonn,easy
AUTHOR
Omar E. Pol, Aug 15 2007
EXTENSIONS
Extended by Ray Chandler, Apr 07 2009
STATUS
approved