%I #23 Nov 23 2024 19:37:51

%S 7,43,59,61,149,151,167,223,239,241,257,293,313,331,347,383,419,421,

%T 491,509,563,601,617,653,743,761,941,1033,1049,1051,1123,1193,1213,

%U 1229,1231,1283,1303,1319,1321,1373,1409,1427,1481,1553,1571,1607,1733

%N Primes whose sum of digits is a multiple of 7.

%H Harry J. Smith, <a href="/A062336/b062336.txt">Table of n, a(n) for n = 1..1000</a>

%e 419 is a prime with sum of digits = 14, hence belongs to the sequence.

%t Select[Prime[Range[300]],Divisible[Total[IntegerDigits[#]],7]&] (* _Harvey P. Dale_, Jun 27 2021 *)

%o (PARI) isok(n) = isprime(n) && sumdigits(n) % 7 == 0 \\ _Harry J. Smith_, Aug 05 2009

%o (Magma) [ p: p in PrimesUpTo(100000) | &+Intseq(p) mod 7 eq 0 ]; // _Vincenzo Librandi_, Apr 02 2011

%K nonn,base,easy

%O 1,1

%A _Amarnath Murthy_, Jun 21 2001

%E More terms from Larry Reeves (larryr(AT)acm.org), Jul 06 2001