|
%I #18 Jan 07 2017 11:44:30
%S 23,67,811,911,1213,2729,3137,3637,4243,4447,4547,5153,5659,6367,6871,
%T 6971,7879,8389,8689,9397,9497,9697,98101,102103,104107,105107,108109,
%U 115127,117127,118127,123127,126127,132137,138139,150151,151157,154157,156157,157163
%N Primes formed from the concatenation of n and nextprime(n).
%H K. D. Bajpai, <a href="/A280376/b280376.txt">Table of n, a(n) for n = 1..10000</a>
%e 811 is in the sequence because it is prime formed from the concatenation of 8 and 11, where 11 is the prime next to 8.
%e 3137 is in the sequence because it is prime formed from the concatenation of 31 and 37, where 37 is the prime next to 31.
%p f:= proc(n) local x,p;
%p p:= nextprime(n);
%p x:= n*10^(1+ilog10(p))+p;
%p if isprime(x) then x else NULL fi
%p end proc:
%p map(f, [$1..200]); # _Robert Israel_, Jan 01 2017
%t Select[Table[FromDigits[Join[IntegerDigits[n], IntegerDigits[NextPrime[n]]]], {n,500}], PrimeQ]
%o (Magma) [p : n in[1 .. 200] | IsPrime (p) where p is Seqint(Intseq (NextPrime(n)) cat Intseq(n))];
%Y Cf. A084667, A084669, A151800.
%Y Subsequence of primes of A049852.
%K nonn,base
%O 1,1
%A _K. D. Bajpai_, Jan 01 2017
|
