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

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A063676 a(1) = 1 and for n > 1 let a(n) = a(n-1) + m, where m is the arithmetic mean of the largest subset of all predecessors such that m is an integer and m is maximal. 2
1, 2, 4, 7, 11, 16, 24, 33, 46, 62, 78, 106, 140, 184, 235, 302, 391, 487, 612, 768, 943, 1155, 1367, 1698, 2075, 2513, 3023, 3649, 4386, 5286, 6306, 7544, 8936, 10408, 12255, 14102, 16590, 19426, 22902, 26902, 31345, 36634, 42707, 49486, 57463 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

LINKS

Table of n, a(n) for n=1..45.

EXAMPLE

The arithmetic mean of the first 7 elements is (1 + 2 + 4 + 7 + 11 + 16 + 24) / 7 = 65 / 7; this is not an integer. But skipping a(5) = 11 yields m = 54 / 6 = 9, so we have a(8) = a(7) + m = 24 + 9 = 33.

MATHEMATICA

a[1] = 1; a[n_] := a[n] = Module[{k, s}, For[k = n-1, k >= 1, k--, s = Select[Mean /@ Subsets[Array[a, n-1], {k}], IntegerQ] // Sort; If[s != {}, Return[a[n-1] + Last[s]]]]]; Table[a[n], {n, 1, 45}] (* Jean-Fran├žois Alcover, Dec 11 2014 *)

CROSSREFS

A063677, A063678.

Sequence in context: A129339 A196719 A011912 * A099385 A331387 A237821

Adjacent sequences:  A063673 A063674 A063675 * A063677 A063678 A063679

KEYWORD

nice,nonn

AUTHOR

Reinhard Zumkeller, Jul 28 2001

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.

License Agreements, Terms of Use, Privacy Policy. .

Last modified May 16 00:49 EDT 2021. Contains 343937 sequences. (Running on oeis4.)