A100971 Integers that are Rhonda numbers to base 12.

560, 800, 3993, 4425, 4602, 4888, 7315, 8296, 9315, 11849, 12028, 13034, 14828, 15052, 16264, 18511, 18906, 25619, 25875, 27176, 32742, 37264, 37523, 46035, 50765, 52338, 58261, 58504, 59166, 62002, 66176, 66752, 66928, 67195, 68502

Offset: 1

Author

Mark Hudson (mrmarkhudson(AT)hotmail.com), Nov 25 2004

Keywords

• easy
• nonn
• base

Comments

See sequence A099542 for the definition of Rhonda numbers and some links. 560 is the smallest integer that is a Rhonda number to some base.

Examples

			The product of the base 12 digits of 560 is 3*10*8=240; the sum of the prime factors of 560 is 4*2+5+7=20; and 240=12*20 so 560 is a Rhonda number to base 12.
		

Links

• Reinhard Zumkeller, Table of n, a(n) for n = 1..1000
• Eric Weisstein's World of Mathematics, Rhonda Number
• Wikipedia, Duodecimal

Crossrefs

Cf. Rhonda numbers to other bases: A100968 (base 4), A100969 (base 6), A100970 (base 8), A100973 (base 9), A099542 (base 10), A100972 (base 14), A100974 (base 15), A100975 (base 16), A255735 (base 18), A255732 (base 20), A255736 (base 30), A255731 (base 60).

Cf. A001414, A027746, A255872.

Column k=6 of A291925.

Programs

Haskell

a100971 n = a100971_list !! (n-1)
a100971_list = filter (rhonda 12) $ iterate z 1 where
   z x = 1 + if r < 11 then x else 12 * z x' where (x', r) = divMod x 12
-- Function rhonda as in A099542.
-- Reinhard Zumkeller, Mar 07 2015