|
| |
|
|
A073609
|
|
a(0) = 2; a(n) for n > 0 is the smallest prime > a(n-1) that differs from a(n-1) by a square.
|
|
7
| |
|
|
2, 3, 7, 11, 47, 83, 227, 263, 587, 911, 947, 983, 1019, 1163, 1307, 1451, 1487, 1523, 1559, 2459, 3359, 4259, 4583, 5483, 5519, 5843, 5879, 6203, 6779, 7103, 7247, 7283, 7607, 7643, 8219, 8363, 10667, 11243, 11279, 11423, 12323, 12647, 12791, 13367
(list; graph; refs; listen; history; internal format)
|
|
|
|
OFFSET
| 0,1
|
|
|
COMMENTS
| For n > 2, a(n) must be of the form k*36 + 11. This is seen by induction since k*36 + 11 + m^2 is even if m is odd and since k*36 + 11 + (m*6 + 2)^2 and k*36 + 11 + (m*6 + 4)^2 are both divisible by 3. - Gerald McGarvey (gerald.mcgarvey(AT)comcast.net), Jun 03 2007
|
|
|
EXAMPLE
| 47 differs from 11 by 36 = 6*6 and no prime between 11 and 47 differs from 11 by a square, so 47 is the next term after 11.
|
|
|
PROG
| (PARI) print1(a=2, ", "); for(n=1, 43, k=1; while(!isprime(b=a+k^2), k++); print1(a=b, ", "))
|
|
|
CROSSREFS
| Sequence in context: A056292 A106125 A175171 * A053781 A066749 A046480
Adjacent sequences: A073606 A073607 A073608 * A073610 A073611 A073612
|
|
|
KEYWORD
| nonn
|
|
|
AUTHOR
| Amarnath Murthy (amarnath_murthy(AT)yahoo.com), Aug 05 2002
|
|
|
EXTENSIONS
| Edited and extended by Klaus Brockhaus (klaus-brockhaus(AT)t-online.de), Aug 07 2002
|
| |
|
|
