

A264526


Smallest number m such that both 2*nm and 2*n+m are primes.


5



1, 1, 3, 3, 1, 3, 3, 1, 3, 9, 5, 3, 9, 1, 9, 3, 5, 9, 3, 1, 3, 15, 5, 3, 9, 7, 3, 15, 1, 9, 3, 5, 15, 3, 1, 15, 3, 5, 9, 15, 5, 3, 9, 7, 9, 15, 7, 9, 3, 1, 3, 3, 1, 3, 15, 13, 15, 9, 7, 9, 15, 13, 21, 21, 5, 3, 27, 1, 9, 15, 5, 33, 9, 1, 15, 3, 7, 9, 3, 5
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OFFSET

2,3


LINKS



FORMULA



MATHEMATICA

snm[n_]:=Module[{m=1}, While[!PrimeQ[2nm]!PrimeQ[2n+m], m=m+2]; m]; Array[ snm, 90, 2] (* Harvey P. Dale, Aug 13 2017, optimized by Ivan N. Ianakiev, Mar 16 2018 *)


PROG

(Haskell)
a264526 = head . a260689_row
(PARI) a(n) = {my(m=1); while(!(isprime(2*nm) && isprime(2*n+m)), m+=2); m; } \\ Michel Marcus, Mar 18 2018


CROSSREFS



KEYWORD

nonn


AUTHOR



STATUS

approved



