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 A228727 Smallest prime of the form k*prime(n) + prime(k*n). 1

%I #18 Sep 04 2013 15:54:05

%S 7,13,23,131,179,229,283,337,107,641,317,163,643,193,1949,523,257,

%T 2053,1021,1933,2477,773,811,401,929,6379,457,6197,5701,1747,547,1949,

%U 1291,2083,647,661,2341,709,1579,2549,2633,1721,4909,2851,857,877,5441,4441

%N Smallest prime of the form k*prime(n) + prime(k*n).

%C Primes of the form 2*prime(n) + prime(2*n): 7, 13, 23, 107, 163, 193, 257, 401, 457, 547, 647, 661, 709, 857, 877, 1201,...

%e a(1)=7 because 7 is prime and 2*prime(1) + prime(2*1) = 4 + 3 = 7.

%e a(2) = 13 because 13 is prime and 2*prime(2) + prime(2*2) = 6 + 7 = 13.

%t Table[k = 1; While[p = k*Prime[n] + Prime[k*n]; ! PrimeQ[p], k++]; p, {n, 100}] (* _T. D. Noe_, Sep 03 2013 *)

%Y Cf. A095304.

%K nonn

%O 1,1

%A _Irina Gerasimova_, Aug 31 2013, Sep 04 2013

%E Corrected by _R. J. Mathar_, Sep 02 2013

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Last modified August 7 03:39 EDT 2024. Contains 375008 sequences. (Running on oeis4.)