A372181 a(n) is the smallest number whose symmetric representation of sigma consists of n copies of unimodal pattern 121 (separated by 0's if n > 1).

6, 78, 1014, 12246, 171366, 1922622, 28960854, 300014754, 4174476774

Offset

1,1

Comments

This sequence is infinite (see A372180).

Links

Table of n, a(n) for n=1..9.

Example

a(2) = 78 is the smallest number whose symmetric representations of sigma has unimodal pattern 1210121.
a(4) = 12246 is the smallest number whose symmetric representations of sigma has unimodal pattern 121012101210121.

Mathematica

(* function seqQ[ ] is defined in A372180 *)
smallest[s_, m_] := NestWhile[#+1&, s, !seqQ[#, m]&]
a372181[n_] := Rest[FoldList[smallest[#1, #2]&, 1, Range[n]]]
a372181[9] (* long computation time *)

Crossrefs

Row 2 of A367377.

Row 1 of A372180.

Cf. A237593.

Sequence in context: A186663 A069670 A074112 * A197103 A345360 A208473

Adjacent sequences: A372178 A372179 A372180 * A372182 A372183 A372184

Keyword

nonn,more

Author

Hartmut F. W. Hoft, Apr 21 2024

Status

approved