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A241525 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. 0
19, 17, 13, 521, 509, 503, 499, 491, 14153, 25793, 25771, 37663, 37657, 98729, 98717, 98713, 98711, 98689, 98669, 98663, 98641, 98639, 98627, 98621, 98597, 98573, 69794393, 69794383, 268684679, 268684651, 268684627, 329788829, 545497787, 545497769, 545497759, 545497753, 545497747, 545497741, 545497727, 545497723, 545497691, 545497681, 545497679, 545497637, 545497633, 545497609 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

No more terms below 2^32

LINKS

Table of n, a(n) for n=1..46.

EXAMPLE

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}.

PROG

(UBASIC)

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

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

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

   40   if K>KM then print K, Q:KM=K

   50   K=0:goto 20

  200   *SODP:S=0:L=alen(P)

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

  220   S=S+D:next I

  230   return

CROSSREFS

Cf. A240598.

Sequence in context: A135734 A215021 A215085 * A321332 A109410 A230339

Adjacent sequences:  A241522 A241523 A241524 * A241526 A241527 A241528

KEYWORD

nonn,base

AUTHOR

Carlos Rivera, Apr 24 2014

STATUS

approved

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Last modified June 16 04:56 EDT 2021. Contains 345056 sequences. (Running on oeis4.)