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A100810 a(n) = 0 if prime(n) + 2 = prime(n+1), otherwise 1. 3
1, 0, 0, 1, 0, 1, 0, 1, 1, 0, 1, 1, 0, 1, 1, 1, 0, 1, 1, 0, 1, 1, 1, 1, 1, 0, 1, 0, 1, 1, 1, 1, 0, 1, 0, 1, 1, 1, 1, 1, 0, 1, 0, 1, 0, 1, 1, 1, 0, 1, 1, 0, 1, 1, 1, 1, 0, 1, 1, 0, 1, 1, 1, 0, 1, 1, 1, 1, 0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 1, 0, 1, 1, 1, 1, 1, 0, 1, 1, 1, 1, 1, 1, 1, 1, 0, 1, 1, 1, 1, 1, 0, 1 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,1
LINKS
FORMULA
a(n) = 1 - A100821(n) = 1 - A062301(n+1).
EXAMPLE
a(2) = 0 because prime(2) + 2 = 5 = prime(3).
a(3) = 0 because prime(3) + 2 = 7 = prime(4).
MAPLE
a:= n-> `if`(isprime(ithprime(n)+2), 0, 1):
seq(a(n), n=1..105); # Alois P. Heinz, Oct 02 2020
MATHEMATICA
Table[If[Prime[n] + 2 == Prime[n + 1], 0, 1], {n, 120}] (* Ray Chandler, Jan 09 2005 *)
If[#[[2]]-#[[1]]==2, 0, 1]&/@Partition[Prime[Range[110]], 2, 1] (* Harvey P. Dale, Mar 05 2016 *)
CROSSREFS
Sequence in context: A204171 A267612 A242252 * A373481 A174889 A005171
KEYWORD
easy,nonn
AUTHOR
Giovanni Teofilatto, Jan 05 2005
EXTENSIONS
Corrected and extended by Ray Chandler, Jan 09 2005
STATUS
approved

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Last modified June 24 09:46 EDT 2024. Contains 373674 sequences. (Running on oeis4.)