|
|
A102552
|
|
a(n) = prime(n)-(prime(n+1)+prime(n-1))/2.
|
|
2
|
|
|
0, -1, 1, -1, 1, -1, -1, 2, -2, 1, 1, -1, -1, 0, 2, -2, 1, 1, -2, 1, -1, -1, 2, 1, -1, 1, -1, -5, 5, -1, 2, -4, 4, -2, 0, 1, -1, 0, 2, -4, 4, -1, 1, -5, 0, 4, 1, -1, -1, 2, -4, 2, 0, 0, 2, -2, 1, 1, -4, -2, 5, 1, -1, -5, 4, -2, 4, -1, -1, -1, 1, 0, 1, -1, -1, 2, -2, -1, 4, -4, 4, -2, 1, -1, -1, 2, 1, -1, -4, 2, 2, -2, 2, -1, -3, 5, -8, 6, -2, 2, 0, 2, -2
(list;
graph;
refs;
listen;
history;
text;
internal format)
|
|
|
OFFSET
|
3,8
|
|
REFERENCES
|
Eric Weisstein, CRC Concise Encyclopedia of Mathematics, 1998, page 1321.
|
|
LINKS
|
|
|
FORMULA
|
|
|
EXAMPLE
|
a(6)=-1 because 13-(17+11)/2=-1.
|
|
MAPLE
|
a:=n->ithprime(n)-(ithprime(n+1)+ithprime(n-1))/2: seq(a(n), n=3..95); # Emeric Deutsch, Mar 02 2005
|
|
MATHEMATICA
|
f[n_] := Prime[n] - (Prime[n - 1] + Prime[n + 1])/2; Table[f[n], {n, 3, 107}] (* Robert G. Wilson v, Sep 25 2006 *)
#[[2]]-(#[[1]]+#[[3]])/2&/@Partition[Prime[Range[2, 110]], 3, 1] (* Harvey P. Dale, Sep 21 2013 *)
|
|
PROG
|
(PARI) a(n) = prime(n)-(prime(n+1)+prime(n-1))/2;
|
|
CROSSREFS
|
|
|
KEYWORD
|
sign
|
|
AUTHOR
|
|
|
EXTENSIONS
|
|
|
STATUS
|
approved
|
|
|
|