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!)
 A182857 Smallest number that requires exactly n iterations to reach a fixed point under the x -> A181819(x) map. 41
 1, 3, 4, 6, 12, 60, 2520, 1286485200, 35933692027611398678865941374040400000 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,2 COMMENTS a(9) has 296 digits. Related to Levine's sequence (A011784): A011784(n) = A001222(a(n)) = A001221(a(n+1)) = A051903(a(n+2)) = A071625(a(n+2)). Also see A182858. Values of n where A182850(n) increases to a record. The multiplicity of prime(k) in a(n+1) is the k-th largest prime index of a(n), which is A296150(a(n),k). - Gus Wiseman, May 13 2018 LINKS Gus Wiseman, Table of n, a(n) for n = 0..9 FORMULA For n > 0, a(n) = A181819(a(n+1)). For n > 1, a(n) = A181821(a(n-1)). EXAMPLE From Gus Wiseman, May 13 2018: (Start) Like A001462 the following sequence of multisets whose Heinz numbers belong to this sequence is a run-length describing sequence, as the number of k's in row n + 1 is equal to the k-th term of row n. {2} {1,1} {1,2} {1,1,2} {1,1,2,3} {1,1,1,2,2,3,4} {1,1,1,1,2,2,2,3,3,4,4,5,6,7} {1,1,1,1,1,1,1,2,2,2,2,2,2,3,3,3,3,3,4,4,4,4,5,5,5,5,6,6,6,7,7,7,8,8,9,9,10,10,11,12,13,14} (End) MATHEMATICA Prepend[Function[m, Times@@Prime/@m]/@NestList[Join@@Table[Table[i, {Reverse[#][[i]]}], {i, Length[#]}]&, {2}, 8], 1] (* Gus Wiseman, May 13 2018 *) CROSSREFS Cf. A001462, A007755, A007916, A009287, A012257, A112798, A181819, A182850-A182858, A296150, A304455, A304464, A304465. Sequence in context: A137333 A006719 A202855 * A251483 A009287 A061080 Adjacent sequences:  A182854 A182855 A182856 * A182858 A182859 A182860 KEYWORD nonn AUTHOR Matthew Vandermast, Jan 05 2011 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 June 21 02:28 EDT 2021. Contains 345342 sequences. (Running on oeis4.)