A160405 - OEIS

%I #9 Sep 08 2022 08:45:45

%S 10007100000310037,10007100000310163,10007100000310247,

%T 10007100000310271,10007100000310289,10007100000310321,

%U 10007100000310433,10007100000310463,10007100000310477

%N Primes that are the concatenation of a 5-digit prime, a 7-digit prime, and a 5-digit prime.

%C Haiku-haiku-haiku primes. I would like to call these "Haiku primes" but it seems that name has been used by _Geoffrey Caveney_ for a different concept. Another possible name would be haiku-formed primes, but maybe that should be reserved for primes which are formed from any number of primes of width 5 or 7. Note that if you associate the hyphens with the central word, Haiku-haiku-haiku is itself of the 5-7-5 form (in characters).

%H Wikipedia, <a href="http://en.wikipedia.org/wiki/Haiku">Haiku</a>

%e 10007, 1000003, 10037, and 10007100000310037 are all prime, so 10007100000310037 is in the sequence.

%o (Magma) [ a: p in PrimesInInterval(10000,10007), q in PrimesInInterval(1000000,1000003), r in PrimesInInterval(10000,12000) | IsPrime(a) where a is Seqint(Intseq(r) cat Intseq(q) cat Intseq(p)) ]; // _Klaus Brockhaus_, May 20 2009

%Y Cf. A000040 (primes), A006879 (number of primes with n digits).

%K base,fini,nonn

%O 1,1

%A _Walter Nissen_, May 13 2009

%E Edited by _Klaus Brockhaus_, May 20 2009