|
|
|
|
0, 0, 0, 1, 1, 0, 0, 1, 2, 2, 1, 1, 0, 1, 2, 1, 1, 1, 2, 2, 1, 2, 2, 2, 2, 1, 0, 1, 2, 2, 2, 2, 2, 2, 1, 1, 0, 0, 1, 1, 1, 2, 3, 4, 4, 3, 3, 3, 4, 4, 3, 3, 4, 4, 3, 2, 2, 2, 3, 4, 3, 2, 1, 2, 3, 2, 3, 2, 2, 2, 2, 2, 1, 2, 3, 2, 2, 3, 3, 4, 3, 4, 3, 4, 5, 5, 5, 5, 5, 4
(list;
graph;
refs;
listen;
history;
text;
internal format)
|
|
|
OFFSET
|
1,9
|
|
LINKS
|
|
|
EXAMPLE
|
|
|
MAPLE
|
f:= proc(t) `if`(isprime(6*t-1), 1, 0) - `if`(isprime(6*t+1), 1, 0) end proc:
ListTools:-PartialSums(map(f, [$1..100])); # Robert Israel, Feb 19 2019
|
|
MATHEMATICA
|
Accumulate@ Boole@ PrimeQ[6 Range@ # - 1] - Accumulate@ Boole@ PrimeQ[6 Range@ # + 1] &@ 60 (* Michael De Vlieger, Jan 27 2019 *)
|
|
PROG
|
(PARI)
isp(n) = isprime(6*n+1); \\ A167021
ism(n) = isprime(6*n-1); \\ A167020
psisp(n) = sum(k=1, n, isp(k)); \\ A172104
psism(n) = sum(k=1, n, ism(k)); \\ A172103
|
|
CROSSREFS
|
|
|
KEYWORD
|
sign
|
|
AUTHOR
|
|
|
EXTENSIONS
|
|
|
STATUS
|
approved
|
|
|
|