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A335190
a(n) is the number of values of k < n for which 4*(a(k) + a(n-k)) <= n.
1
0, 1, 0, 2, 2, 1, 2, 6, 2, 4, 0, 5, 4, 2, 6, 8, 4, 7, 2, 8, 6, 3, 10, 12, 6, 10, 4, 11, 8, 4, 12, 14, 8, 13, 6, 14, 10, 5, 14, 18, 10, 14, 8, 17, 10, 10, 18, 20, 14, 17, 12, 20, 10, 13, 16, 22, 16, 14, 14, 25, 10, 14, 16, 24, 22, 19, 16, 28, 12, 17, 20, 30, 24
OFFSET
1,4
COMMENTS
This sequence is a variant of A335060.
Graphically, we have an overlay of four curves that correspond to the quadrisections of the sequence.
EXAMPLE
The first terms, alongside the corresponding k's, are:
n a(n) k's
-- ---- ---------------------
1 0 {}
2 1 {1}
3 0 {}
4 2 {1, 3}
5 2 {2, 3}
6 1 {3}
7 2 {1, 6}
8 6 {1, 2, 3, 5, 6, 7}
9 2 {3, 6}
10 4 {1, 3, 7, 9}
11 0 {}
12 5 {1, 3, 6, 9, 11}
PROG
(PARI) for (n=1, #a=vector(73), print1 (a[n]=sum(k=1, n-1, a[k]+a[n-k]<=n/4)", "))
CROSSREFS
Cf. A335060.
Sequence in context: A091562 A106585 A057227 * A283170 A368836 A336823
KEYWORD
nonn,look
AUTHOR
Rémy Sigrist, May 26 2020
STATUS
approved