OFFSET
1,2
COMMENTS
Similar to A278055 but with different starting values.
a(1015) = 1036. This is the smallest index for which a(n) > n. So, without the condition that a(n) = 0 for n <= 0, this sequence would be finite and have exactly 1015 terms.
Much like the Hofstadter Q-sequence A005185, it is not known if this sequence is defined for all positive n.
a(n) exists for n <= 3*10^7.
LINKS
Nathan Fox, Table of n, a(n) for n = 1..10000
MATHEMATICA
a[n_] := a[n] = Which[n < 1, 0, n < 11, n, True, a[n-a[n-1]] + a[n-a[n-2]] + a[n-a[n-3]]]; Array[a, 100] (* Paolo Xausa, May 31 2024 *)
CROSSREFS
KEYWORD
nonn
AUTHOR
Nathan Fox, May 28 2024
STATUS
approved