login
A095184
a(1) = 3; for n > 1 a(n) is the least prime of form a(n-1) + k*prime(n-1) with k > 0.
1
3, 5, 11, 31, 59, 103, 181, 283, 359, 727, 1249, 1373, 1447, 1693, 1951, 2609, 2927, 3163, 3407, 3541, 3967, 4259, 4733, 5231, 6121, 6703, 7309, 7927, 8783, 9001, 9227, 10243, 12601, 13697, 15643, 17431, 20149, 23603, 23929, 25933, 30431, 31147
OFFSET
1,1
EXAMPLE
For n = 4 we have a(n-1) = a(3) = 11, prime(n-1) = prime(3) = 5; a(3) + k*prime(3) = 11 + k*5 gives 16 for k = 1, 21 for k = 2, 26 for k = 3 and prime 31 for k = 4, hence a(4) = 31.
PROG
(PARI) {for(n=1, 42, if(n==1, a=3, p=prime(n-1); k=1; while(!isprime(r=a+k*p), k++); a=r); print1(a, ", "))}
CROSSREFS
Cf. A085041. [R. J. Mathar, Sep 04 2008]
Sequence in context: A165572 A246901 A236568 * A048235 A154939 A121926
KEYWORD
nonn,easy
AUTHOR
Amarnath Murthy, Jun 02 2004
EXTENSIONS
Edited and extended by Klaus Brockhaus, Jun 04 2004
STATUS
approved