OFFSET
1,4
COMMENTS
Let b(n) denote the number of k with 0<=k<=n such that floor((3/2)^k) = A002379(k) is even; then a(n) = n-2*b(n).
Equivalently: let c(n) denote the number of k, 0<=k<=n, such that floor((3/2)^k) = A002379(k) is odd, then a(n) = 2*c(n)-n.
Is a(n)>0? For n large enough does a(n)>sqrt(n) always hold?
Conjecture: asymptotically, a(n) ~ C * Log(n)^2 with C = 1.4.....
LINKS
Robert G. Wilson v, Graph of first 100000 terms
FORMULA
a(n) = (-1) * Sum_{i=1..n} (-1)^A002379(i).
MATHEMATICA
a[0] = 0; a[n_] := a[n] = a[n - 1] - (-1)^Floor[(3/2)^n]; Table[ a[n], {n, 0, 95}]
PROG
(PARI) a(n)=-sum(i=1, n, sign((-1)^floor((3/2)^i)))
(PARI) a(n)=n-2*sum(k=0, n, if(floor((3/2)^k)%2, 0, 1))
CROSSREFS
KEYWORD
easy,nonn
AUTHOR
Benoit Cloitre, Jun 20 2002
EXTENSIONS
Edited by Ralf Stephan, Sep 01 2004
STATUS
approved