The OEIS Foundation is supported by donations from users of the OEIS and by a grant from the Simons Foundation.

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A131810 Additive persistence of Catalan numbers. 1
 0, 0, 0, 0, 1, 1, 1, 2, 1, 2, 3, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 3, 3, 2, 2, 2, 2, 3, 3, 3, 3, 3, 3, 3, 3, 3, 2, 3, 3, 3, 3, 2, 3, 2, 2, 3, 2, 2, 2, 2, 2, 2, 2, 2, 2, 3, 3, 3, 2, 2, 2, 2, 3, 3, 3, 3, 3, 3, 2, 2, 2, 3, 2, 3, 2, 2, 2, 3, 3, 2, 2, 2, 3, 2, 4, 3, 2, 3 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,8 LINKS EXAMPLE Catalan number 429 -> 4+2+9=15 -> 1+5=6 thus persistence is 2 MAPLE with(numtheory): with(combinat): P:=proc(n) local a, t; t:=0; a:=(2*n)!/(n!*(n+1)!); while a>9 do t:=t+1; a:=convert(convert(a, base, 10), `+`); od; t; end: seq(P(i), i=0..10^2); CROSSREFS Cf. A003001, A006050, A000108, A131809. Sequence in context: A182598 A331084 A067694 * A233519 A192295 A037195 Adjacent sequences:  A131807 A131808 A131809 * A131811 A131812 A131813 KEYWORD easy,nonn,base AUTHOR Paolo P. Lava and Giorgio Balzarotti, Jul 18 2007 EXTENSIONS Corrected entries and Maple code by Paolo P. Lava, Dec 19 2017 STATUS approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

Last modified May 28 01:48 EDT 2020. Contains 334671 sequences. (Running on oeis4.)