|
| |
|
|
A113709
|
|
a(n) is the composite between p(n) and p(n+1), where p(n) is the n-th prime, which is divisible by (p(n+1)-p(n)).
|
|
9
| |
|
|
4, 6, 8, 12, 16, 18, 20, 24, 30, 36, 40, 42, 44, 48, 54, 60, 66, 68, 72, 78, 80, 84, 96, 100, 102, 104, 108, 112, 126, 128, 132, 138, 140, 150, 156, 162, 164, 168, 174, 180, 190, 192, 196, 198, 204, 216, 224, 228, 232, 234, 240, 250, 252, 258, 264, 270, 276, 280
(list; graph; refs; listen; history; internal format)
|
|
|
|
OFFSET
| 2,1
|
|
|
COMMENTS
| Exactly one composite exists between each p(n+1) and p(n) which is divisible by (p(n+1)-p(n)), for n >= 2.
|
|
|
FORMULA
| a(n)=p(n+1) - (p(n) (mod p(n+1)-p(n))).
|
|
|
EXAMPLE
| Between the primes 67 and 71 is the composite 68 and 68 is divisible by (71-67)=4. So 68 is in the sequence.
|
|
|
MATHEMATICA
| f[n_] := Block[{p = Prime[n], q = Prime[n + 1]}, q - Mod[p, q - p]]; Table[ f[n], {n, 2, 60}] (* Robert G. Wilson v *)
|
|
|
CROSSREFS
| Cf. A113710, A111379.
Sequence in context: A199768 A157932 A097619 * A076082 A162648 A062554
Adjacent sequences: A113706 A113707 A113708 * A113710 A113711 A113712
|
|
|
KEYWORD
| nonn
|
|
|
AUTHOR
| Leroy Quet Nov 06 2005
|
|
|
EXTENSIONS
| More terms from Don Reble and Robert G. Wilson v (rgwv(AT)rgwv.com), Nov 07 2005
|
| |
|
|
