|
|
A297828
|
|
Difference sequence of A297997.
|
|
2
|
|
|
1, 1, 1, 2, 2, 2, 1, 1, 2, 1, 2, 1, 3, 2, 1, 1, 3, 1, 1, 3, 1, 1, 1, 1, 2, 3, 2, 1, 1, 1, 1, 2, 2, 1, 1, 1, 1, 2, 2, 2, 2, 1, 1, 2, 1, 1, 1, 2, 3, 2, 2, 2, 1, 1, 2, 1, 3, 2, 2, 2, 1, 1, 2, 1, 2, 1, 2, 1, 3, 2, 1, 1, 3, 2, 2, 1, 1, 2, 1, 1, 1, 2, 2, 1, 2, 1
(list;
graph;
refs;
listen;
history;
text;
internal format)
|
|
|
OFFSET
|
1,4
|
|
COMMENTS
|
Conjectures:
(1) 2 <= a(k) <= 4 for k>=1;
(2) if d is in {1,2,3}, then a(k) = d for infinitely many k.
|
|
LINKS
|
|
|
MATHEMATICA
|
mex[list_, start_] := (NestWhile[# + 1 &, start, MemberQ[list, #] &]);
tbl = {}; a[0] = 1; a[1] = 2; b[0] = 3; b[1] = 4;
a[n_] := a[n] = a[1]*b[n - 1] - a[0]*b[n - 2] + n;
b[n_] := b[n] = mex[tbl = Join[{a[n], a[n - 1], b[n - 1]}, tbl], b[n - 1]];
u = Table[a[n], {n, 0, 300}](* A297826 *)
v = Table[b[n], {n, 0, 300}](* A297997 *)
|
|
CROSSREFS
|
|
|
KEYWORD
|
nonn,easy
|
|
AUTHOR
|
|
|
STATUS
|
approved
|
|
|
|