A241525 - OEIS

%I #13 May 05 2014 11:23:33

%S 19,17,13,521,509,503,499,491,14153,25793,25771,37663,37657,98729,

%T 98717,98713,98711,98689,98669,98663,98641,98639,98627,98621,98597,

%U 98573,69794393,69794383,268684679,268684651,268684627,329788829,545497787,545497769,545497759,545497753,545497747,545497741,545497727,545497723,545497691,545497681,545497679,545497637,545497633,545497609

%N a(n) is the smallest start of a run of exactly n consecutive primes such that the sum of the digits of each prime is composite.

%C No more terms below 2^32

%e a(3)=13 because the run of the 3 consecutive primes {13, 17, 19} is such that the sum of digits for each prime is {4, 8, 10}.

%o (UBASIC)

%o    10   P=1:KM=0:K=0:'puzzle 1290, Meller

%o    20   P=nxtprm(P):if P>2^32-20 then end

%o    30   gosub *SODP:if S<>prmdiv(S) then K=K+1:Q=P:goto 20

%o    40   if K>KM then print K, Q:KM=K

%o    50   K=0:goto 20

%o   200   *SODP:S=0:L=alen(P)

%o   210   for I=1 to L:D=val(mid(str(P), I+1, 1))

%o   220   S=S+D:next I

%o   230   return

%Y Cf. A240598.

%K nonn,base

%O 1,1

%A _Carlos Rivera_, Apr 24 2014