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A227783
Stufe of Q(sqrt(-k)), where k is the n-th squarefree number.
2
1, 2, 2, 2, 2, 4, 2, 2, 2, 2, 4, 2, 2, 2, 2, 4, 2, 2, 2, 4, 2, 2, 2, 2, 2, 4, 2, 2, 2, 2, 4, 2, 2, 4, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 4, 2, 2, 2, 2, 4, 2, 2, 2, 2, 4, 2, 2, 2, 2, 4, 2, 2, 2, 4, 2, 2, 2, 2, 2, 4, 2, 2, 2, 2, 4, 2, 2, 4, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 4, 2, 2, 2, 4
OFFSET
1,2
COMMENTS
A227782 is the main entry for this sequence.
LINKS
Charles R Greathouse IV, Table of n, a(n) for n = 1..10000
FORMULA
a(n) = A227782(A005117(n)).
PROG
(PARI) apply(n->if(n%8==7, 4, if(n>1, 2, 1)), select(issquarefree, vector(200, i, i)))
CROSSREFS
Sequence in context: A367515 A122066 A053238 * A216321 A058263 A232398
KEYWORD
nonn,easy
AUTHOR
STATUS
approved