OFFSET
1,2
COMMENTS
The sequence is not increasing with the maximum width of the symmetric representation just like A347979.
Observation: a(2)..a(14) ending in 5. - Omar E. Pol, Sep 23 2021
EXAMPLE
The pattern of maximum widths of the parts in the symmetric representation of sigma for the first four terms in the sequence is:
a(n) parts successive widths
1: 1 1
15: 3 1 2 1
315: 3 1 3 1
2145: 7 1 2 3 4 3 2 1
MATHEMATICA
a262045[n_] := Module[{a=Accumulate[Map[If[Mod[n - # (#+1)/2, #]==0, (-1)^(#+1), 0] &, Range[Floor[(Sqrt[8n+1]-1)/2]]]]}, Join[a, Reverse[a]]]
a347980[n_, mw_] := Module[{list=Table[0, mw], i, v}, For[i=1, i<=n, i+=2, v=Max[a262045[i]]; If [list[[v]]==0, list[[v]]=i]]; list]
a347980[2500000, 14] (* long evaluation time *)
CROSSREFS
KEYWORD
nonn,more
AUTHOR
Hartmut F. W. Hoft, Sep 22 2021
STATUS
approved