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Rhonda numbers in sexagesimal number system.
14

%I #10 Feb 16 2025 08:33:25

%S 3348,3510,6750,17430,18750,18876,18944,19475,20564,21312,26550,28280,

%T 37230,38396,43940,48042,77770,88270,91224,97470,108882,111403,120046,

%U 123630,181996,182646,235467,253460,260429,264735,278675,289161,295960,296055,306642

%N Rhonda numbers in sexagesimal number system.

%C See A099542 for definition of Rhonda numbers and for more links.

%H Reinhard Zumkeller, <a href="/A255731/b255731.txt">Table of n, a(n) for n = 1..1000</a>

%H Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/RhondaNumber.html">Rhonda Number</a>

%H Wikipedia, <a href="http://www.wikipedia.org/wiki/Sexagesimal">Sexagesimal</a>

%e a(1) = 3348 = 55 * 60^1 + 48 * 60^0 = 2*2*3*3*3*31,

%e with 55 * 48 = 60 * (2+2+3+3+3+31) = 2640;

%e a(10) = 21312 = 5*60^2 + 55*60^1 + 12*60^0 = 2*2*2*2*2*2*3*3*37,

%e with 5 * 55 * 12 = 60 * (2+2+2+2+2+2+3+3+37) = 3300.

%o (Haskell)

%o a255731 n = a255731_list !! (n-1)

%o a255731_list = filter (rhonda 60) $ iterate z 1 where

%o z x = 1 + if r < 59 then x else 60 * z x' where (x', r) = divMod x 60

%o -- Function rhonda as in A099542.

%Y Cf. Rhonda numbers to other bases: A100968 (base 4), A100969 (base 6), A100970 (base 8), A100973 (base 9), A099542 (base 10), A100971 (base 12), A100972 (base 14), A100974 (base 15), A100975 (base 16), A255735 (base 18), A255732 (base 20), A255736 (base 30).

%Y Cf. A001414, A027746.

%Y Column k=42 of A291925.

%K nonn,base,changed

%O 1,1

%A _Reinhard Zumkeller_, Mar 05 2015