OFFSET
1,2
COMMENTS
This sequence lists all nonnegative numbers in A368945, all of which are even.
Conjecture: Every nonnegative even number occurs in this sequence.
EXAMPLE
MATHEMATICA
a071561Q[n_] := Select[Divisors[n], Sqrt[n/2]<=#<Sqrt[2n]&]=={}
t249223[n_] := FoldList[#1+(-1)^(#2+1)KroneckerDelta[Mod[n-#2 (#2+1)/2, #2]]&, 1, Range[2, Floor[(Sqrt[8n+1]-1)/2]]] (* row n in triangle of A249223 *)
zeroExt[n_] := Module[{s=Position[t249223[n], 1][[-1, -1]]}, 2 Ceiling[(n+1)/(s+1)-(s+1)/2]-2]
a368609[n_] := Map[zeroExt, Select[Range[n], a071561Q]]
a368609[135]
CROSSREFS
KEYWORD
nonn
AUTHOR
Hartmut F. W. Hoft, Jan 25 2024
STATUS
approved