A117094 Numbers k such that nextprime(5*k) > 5*nextprime(k) (if p is prime then nextprime(p) = p).
2, 3, 5, 7, 11, 13, 17, 18, 19, 23, 28, 29, 31, 37, 40, 41, 43, 47, 53, 59, 60, 61, 67, 71, 72, 73, 78, 79, 82, 83, 89, 96, 97, 101, 102, 103, 105, 106, 107, 109, 113, 127, 131, 137, 139, 149, 151, 155, 156, 157, 163, 166, 167, 173, 178, 179, 180, 181, 191, 192, 193, 197, 199, 211, 222, 223, 226
Offset: 1
Examples
13 is a term since nextprime(5*13) = 67 and nextprime(5)*nextprime(13) = 5*13=65 and 67 > 65.
Links
- Robert Israel, Table of n, a(n) for n = 1..10000
Programs
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Maple
select(n -> nextprime(5*n) > 5*nextprime(n-1), [$1..1000]); # Robert Israel, Jul 25 2025
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Mathematica
Select[Range[250], NextPrime[5*#] > 5*NextPrime[# - 1] &] (* Paolo Xausa, Jul 28 2025 *)
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PARI
for(i=1,150,if(nextprime(5*i)>nextprime(5)*nextprime(i),print1(i,",")))
Extensions
More terms from Robert Israel, Jul 25 2025
Comments