A072063 Smallest prime of form prime(n)+k*n, k>0.
3, 5, 11, 11, 31, 19, 31, 43, 41, 59, 53, 61, 67, 71, 107, 101, 127, 79, 181, 131, 157, 101, 313, 113, 197, 127, 157, 163, 167, 173, 251, 163, 269, 173, 359, 223, 379, 239, 401, 293, 1163, 223, 277, 281, 467, 337, 587, 271, 521, 379, 641, 499
Offset: 1
Keywords
Examples
n=3, prime(3)=5: 5+1*3=8 is not prime, but 5+2*3=11, therefore a(3)=11 and A072064(3)=2.
Links
- Robert Israel, Table of n, a(n) for n = 1..10000
Programs
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Maple
f:= proc(n) local p,k,k0; p:= ithprime(n); if n::odd then k0:= 2 else k0:= 1 fi; for k from k0 by k0 do if isprime(p+k*n) then return p+k*n fi od: end proc: f(1):= 3: map(f, [$1..100]); # Robert Israel, Nov 27 2023 -
Mathematica
sp[n_]:=Module[{p=Prime[n],k=1},While[!PrimeQ[p+k*n],k++];p+k*n]; Array[ sp,60] (* Harvey P. Dale, Apr 19 2019 *) -
PARI
a072063(n) = {my (p=prime(n), j); for (k=1, oo, if(isprime(j=p+k*n), return(j)))}; \\ Hugo Pfoertner, Nov 27 2023
Comments