login
A132230
Primes congruent to 1 (mod 30).
22
31, 61, 151, 181, 211, 241, 271, 331, 421, 541, 571, 601, 631, 661, 691, 751, 811, 991, 1021, 1051, 1171, 1201, 1231, 1291, 1321, 1381, 1471, 1531, 1621, 1741, 1801, 1831, 1861, 1951, 2011, 2131, 2161, 2221, 2251, 2281, 2311, 2341, 2371, 2521, 2551, 2671
OFFSET
1,1
COMMENTS
Also primes congruent to 1 (mod 15). - N. J. A. Sloane, Jul 11 2008
Primes ending in 1 with (SOD-1)/3 integer where SOD is sum of digits. - Ki Punches, Feb 04 2009
FORMULA
a(n) = A111175(n)*30 + 1. - Ray Chandler, Apr 07 2009
Intersection of A030430 and A002476. - Ray Chandler, Apr 07 2009
EXAMPLE
From Muniru A Asiru, Nov 01 2017: (Start)
31 is a prime and 31 = 30*1 + 1;
61 is a prime and 61 = 30*2 + 1;
151 is a prime and 151 = 30*5 + 1;
211 is a prime and 211 = 30*7 + 1;
241 is a prime and 241 = 30*8 + 1;
271 is a prime and 271 = 30*9 + 1.
(End)
MAPLE
select(isprime, [seq(i, i=1..1000, 30)]); # Robert Israel, Jan 19 2016
MATHEMATICA
Select[Range[1, 3000, 30], PrimeQ] (* Vladimir Joseph Stephan Orlovsky, Feb 19 2012 *)
Select[Prime[Range[400]], Mod[#, 30]==1&] (* Harvey P. Dale, May 21 2021 *)
PROG
(PARI) is(n)=isprime(n) && n%30==1 \\ Charles R Greathouse IV, Jul 01 2016
(GAP) A132230 := Filtered(Filtered([1..10^6], n -> n mod 30 = 1), IsPrime); # Muniru A Asiru, Nov 01 2017
KEYWORD
nonn,easy
AUTHOR
Omar E. Pol, Aug 15 2007
EXTENSIONS
Edited by Ray Chandler, Apr 07 2009
STATUS
approved