A114102 Number of partitions of n such that all parts of a partition have the same digital root.
1, 2, 2, 3, 2, 4, 2, 4, 3, 4, 3, 7, 4, 5, 7, 6, 5, 8, 5, 8, 11, 8, 7, 16, 9, 10, 13, 12, 10, 22, 11, 15, 23, 16, 16, 26, 16, 18, 32, 22, 21, 41, 24, 27, 40, 28, 26, 55, 30, 36, 59, 40, 38, 65, 41, 45, 77, 48, 51, 95, 57, 60, 97, 66, 63, 119, 68, 80, 131, 89, 85, 150, 91, 96, 166, 104
Offset: 1
Examples
a(10) = #{10, 5+5, 2+2+2+2+2, 10x1} = 4; a(11) = #{11, 10+1, 11x1} = 3; a(12) = #{12, 10+1+1, 6+6, 4+4+4, 3+3+3+3, 2+2+2+2+2+2, 12x1} = 7.
Links
- Eric Weisstein's World of Mathematics, Digital Root
Crossrefs
Cf. A010888.
A147706. [From Reinhard Zumkeller, Nov 11 2008]
A156144. [From Reinhard Zumkeller, Feb 05 2009]
Programs
-
Haskell
a114102 n = length $ filter (== 1) $ map (length . nub . (map a010888)) $ ps 1 n where ps x 0 = [[]] ps x y = [t:ts | t <- [x..y], ts <- ps t (y - t)] -- Reinhard Zumkeller, Feb 04 2014
Comments