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
Examples
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.
Programs
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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 *)
Comments