A306303 Numbers that appear in the concatenation in decreasing order of their aliquot parts.
95, 110, 220, 312, 330, 371, 432, 440, 510, 525, 550, 624, 660, 714, 770, 864, 880, 936, 990, 995, 1111, 2480, 4100, 5115, 5125, 5134, 5135, 5625, 6120, 6432, 6794, 8100, 8145, 9225, 9864, 9950, 9995, 10250, 11100, 11110, 12864, 15375, 16200, 20500, 22200, 22220
Offset: 1
Examples
Aliquot parts of 95 are 1, 5, 19 and their concatenation in decreasing order is 1951 where 95 appears.
Links
- Paolo P. Lava, Table of n, a(n) for n = 1..250
Programs
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Maple
with(numtheory): P:=proc(n) local a,b,k; a:=sort([op(divisors(n) minus {n})]); b:=a[nops(a)]; for k from nops(a) by -1 to 2 do b:=b*10^(ilog10(a[k-1])+1)+a[k-1]; od; if searchtext(convert(n,string),convert(b,string))>0 then n; fi; end: seq(P(i),i=2..22220); -
Mathematica
Select[Range[23000],SequenceCount[Flatten[IntegerDigits/@Reverse[Most[Divisors[ #]]]],IntegerDigits[ #]]>0&] (* Harvey P. Dale, Nov 20 2023 *)
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