|
Search: id:A099381
|
|
|
| A099381 |
|
Numbers n such that |Fibonacci(n) - prime(n)| is prime. |
|
+0
1
|
|
| 2, 3, 6, 8, 9, 12, 15, 24, 33, 48, 225, 525, 948, 1344, 5169, 30600, 32520, 32604, 72396
(list; graph; listen)
|
|
|
OFFSET
|
1,1
|
|
|
COMMENT
|
Fibonacci(n) - prime(n) > 0 for n >= 8. All terms other than 2 and 8 (only two terms producing 2, the only even prime) are divisible by 3 (as Fibonacci(n) is even - and hence |Fibonacci(n) - prime(n)| > 1 and odd - iff n is divisible by 3).
Some of the larger entries may only correspond to probable primes.
|
|
EXAMPLE
|
9 is a term as Fibonacci(9) - prime(9) = 34 - 23 = 11, a prime.
|
|
MATHEMATICA
|
fQ[n_] := PrimeQ[ Fibonacci[n] - Prime[n]]; Do[ If[ fQ[n], Print[n]], {n, 9, 10^4, 3}] (from Robert G. Wilson v Nov 18 2004)
|
|
PROGRAM
|
(PARI) print1(2, ", ", 3, ", ", 6, ", ", 8, ", "); forstep(n=9, 5169, 3, if(isprime(fibonacci(n)-prime(n)), print1(n, ", ")))
|
|
CROSSREFS
|
Cf. A050180 (Fibonacci(n) + prime(n) is prime).
Sequence in context: A032711 A047244 A111215 this_sequence A089437 A146768 A122479
Adjacent sequences: A099378 A099379 A099380 this_sequence A099382 A099383 A099384
|
|
KEYWORD
|
nonn
|
|
AUTHOR
|
Rick L. Shepherd (rshepherd2(AT)hotmail.com), Nov 16 2004
|
|
EXTENSIONS
|
4 more terms from Jason Earls (zevi_35711(AT)yahoo.com), Nov 25 2007
|
|
|
Search completed in 0.002 seconds
|
