A167608 - OEIS

%I #10 Apr 28 2014 05:23:01

%S 10,9,12,15,15,18,21,27,18,12,15,15,24,30,18,21,27,15,18,27,33,24,27,

%T 27,30,33,30,24,30,36,33,33,39,30,36,39,39,42,27,33,39,15,27,30,18,33,

%U 24,18,24,27,27,36,39,33,33,39,30,27,36,42,42,39,42,48,33,30,21,18,27,33,36,27,33,39,27,36,33,27,39

%N Digit sum of cousin prime pairs.

%C Except for the first term, all the others are multiples of 3.

%H Vincenzo Librandi, <a href="/A167608/b167608.txt">Table of n, a(n) for n = 1..5000</a>

%H Eric Weisstein's World of Mathematics, <a href="http://mathworld.wolfram.com/CousinPrimes.html">Cousin Primes</a>

%e The digit sum of the cousin prime pairs 223 and 227 is: 2+2+3+2+2+7 = 18.

%t cptot[n_]:=Total[Join[IntegerDigits[n],IntegerDigits[n+4]]]; cptot/@Select[ Prime[Range[500]],PrimeQ[#+4]&] (* _Harvey P. Dale_, Apr 27 2014 *)

%Y Cf. A023200, A166173, A167607

%K base,nonn

%O 1,1

%A _Parthasarathy Nambi_, Nov 07 2009