|
| |
|
|
A102632
|
|
Smallest k such that at least one of 2^k+/-prime(n) is prime.
|
|
2
| |
|
|
0, 1, 1, 2, 1, 2, 1, 2, 3, 1, 4, 2, 1, 2, 5, 3, 1, 6, 2, 1, 4, 2, 7, 3, 2, 1, 2, 1, 2, 7, 2, 3, 1, 9, 1, 4, 4, 2, 5, 3, 1, 4, 1, 2, 1, 6, 4, 2, 1, 2, 3, 1, 4, 5, 9, 3, 1, 9, 2, 1, 6, 7, 2, 1, 2, 5, 4, 4, 1, 2, 16, 3, 4, 4, 2, 10, 3, 2, 3, 9, 1, 8, 1, 4, 2, 7, 3, 2, 1, 2, 5, 3, 2, 3, 2, 7, 5, 1, 6, 4, 4, 9, 3, 1
(list; graph; refs; listen; history; internal format)
|
|
|
|
OFFSET
| 1,4
|
|
|
LINKS
| Lei Zhou, Between 2^n and primes.
|
|
|
EXAMPLE
| For prime(2)=3, 2^1+3 = 5 is prime
For prime(18)=61, 2^6-61 = 3 is prime
|
|
|
MATHEMATICA
| f[n_] := Block[{k = 0, p = Prime[n]}, While[ Not[(2^k - p > 1 && PrimeQ[2^k - p]) || PrimeQ[2^k + p]], k++ ]; k]; Table[ f[n], {n, 104}] (from Robert G. Wilson v Jan 22 2005)
|
|
|
CROSSREFS
| Cf. A102930, A102931, A094076, first occurrence in A103032.
Sequence in context: A028334 A083269 A097306 * A094076 A089611 A082067
Adjacent sequences: A102629 A102630 A102631 * A102633 A102634 A102635
|
|
|
KEYWORD
| nonn
|
|
|
AUTHOR
| Lei Zhou (lzhou5(AT)emory.edu), Jan 20 2005
|
|
|
EXTENSIONS
| More terms from Robert G. Wilson v (rgwv(AT)rgwv.com), Jan 21 2005
|
| |
|
|
