|
Search: id:A088420
|
|
|
| A088420 |
|
Number of primes in arithmetic progression starting with 3 and with d=2n. |
|
+0
11
|
|
| 3, 3, 1, 3, 3, 1, 3, 2, 1, 3, 1, 1, 2, 3, 1, 1, 3, 1, 3, 3, 1, 2, 1, 1, 3, 1, 1, 2, 2, 1, 1, 3, 1, 3, 2, 1, 1, 2, 1, 3, 1, 1, 2, 1, 1, 1, 3, 1, 3, 2, 1, 3, 2, 1, 3, 1, 1, 1, 1, 1, 1, 3, 1, 2, 1, 1, 3, 2, 1, 1, 1, 1, 2, 2, 1, 1, 3, 1, 1, 2, 1, 3, 1, 1, 2, 1, 1, 2, 3, 1, 1, 1, 1, 3, 3, 1, 2, 2, 1, 1
(list; graph; listen)
|
|
|
OFFSET
|
1,1
|
|
|
COMMENT
|
Arithmetic progression is stopped when next term is not prime. E.g. for n=5, a=3, that is 3,13,23 are prime, while next term, 33, is not prime.
a(n) <= 3 because 3+3*d is divisible by 3. [From Klaus Brockhaus (klaus-brockhaus(AT)t-online.de), May 14 2009]
|
|
PROGRAM
|
(MAGMA) npap3:=function(d) c:=1; p:=3+d; while IsPrime(p) do c+:=1; p+:=d; end while; return c; end function; [ npap3(2*n): n in [1..105] ]; [From Klaus Brockhaus (klaus-brockhaus(AT)t-online.de), May 14 2009]
|
|
CROSSREFS
|
Cf. A088421, A088422, A088423, A088424, A088425, A088426, A088427, A088428, A088429.
Cf. A115334. [From Klaus Brockhaus (klaus-brockhaus(AT)t-online.de), May 14 2009]
Sequence in context: A068119 A039992 A101988 this_sequence A103585 A154595 A144437
Adjacent sequences: A088417 A088418 A088419 this_sequence A088421 A088422 A088423
|
|
KEYWORD
|
easy,nonn
|
|
AUTHOR
|
Zak Seidov (zakseidov(AT)yahoo.com), Sep 29 2003
|
|
|
Search completed in 0.002 seconds
|
