A338928 Record values of A338565.
1, 2, 3, 4, 7, 17, 21, 38, 58, 82, 148, 174, 176, 360, 362, 479, 846, 1289, 1934, 2196, 3315, 4326, 5701, 8225, 8910, 9507, 11346, 14262, 19832, 25072, 30279, 34638, 46714, 67520, 78082, 82112, 94916, 107902, 175532, 195760, 273164, 275892, 443284, 479324
Offset: 1
Keywords
Programs
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Maple
ispali:= proc(n) local L; L:= convert(n,base,10); evalb(L = ListTools:-Reverse(L)) end proc: N:= 200000: # for terms <= N Palis:= select(ispali, {$2..N}): A338565:= Vector(N): A338565[1]:= 1: R:= 1: bestv:= 1: A[1]:= 1: for n from 2 to N do A[n]:= add(A[n/d], d= numtheory:-divisors(n) intersect Palis); if A[n] > bestv then bestv:= A[n]; R:= R, bestv od: R; -
Mathematica
Block[{a}, a[n_] := If[n == 1, n, Sum[If[(d < n && PalindromeQ[n/d]), a[d], 0], {d, Divisors[n]}]]; Union@ FoldList[Max, Array[a, 10^4]]] (* Michael De Vlieger, Nov 15 2020 *)