A095183 a(n) = least prime of the form prime(n+1) + k*prime(n).

5, 11, 17, 53, 79, 43, 53, 61, 167, 89, 223, 263, 617, 563, 241, 271, 179, 311, 607, 499, 809, 241, 421, 631, 683, 709, 313, 751, 331, 353, 2417, 661, 1783, 983, 449, 761, 1733, 1471, 3847, 1217, 1613, 1277, 1721, 1741, 593, 3793, 1489, 673, 683, 691, 1171, 719

Offset

1,1

Links

Michael B. Porter, Table of n, a(n) for n = 1..10000

Example

For n = 3 we have prime(n+1) = 7, prime(n) = 5; 17 is the least prime of form 7 + k*5, so a(3) =17.

Maple

R:= 5: q:= 3:
for n from 2 to 100 do
  p:= q; q:= nextprime(p);
  for k from 2 by 2 do
    if isprime(q+k*p) then R:= R, q+k*p; break fi
  od
od:
R; # Robert Israel, Nov 28 2025

Mathematica

lpf[n_]:=Module[{k=1, np=NextPrime[n]}, While[!PrimeQ[k*n+np], k++]; k*n+np]; lpf/@Prime[Range[60]] (* Harvey P. Dale, Jan 23 2016 *)

Prog

(PARI) {m=250; q=2; p=3; while(p<m, k=1; while(!isprime(a=p+k*q), k++); print1(a, ", "); q=p; p=nextprime(p+1))}

Crossrefs

Sequence in context: A375313 A174858 A246704 * A018730 A050836 A058019

Adjacent sequences: A095180 A095181 A095182 * A095184 A095185 A095186

Keyword

nonn,look

Author

Amarnath Murthy, Jun 02 2004

Extensions

Edited and extended by Klaus Brockhaus, Jun 03 2004

Status

approved