login
This site is supported by donations to The OEIS Foundation.
Logo

Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A065095 a(1) = 1, a(n+1) is the sum of a(n) and ceiling( arithmetic mean of a(1) ... a(n) ). 8
1, 2, 4, 7, 11, 16, 23, 33, 46, 62, 83, 110, 144, 186, 238, 303, 383, 481, 600, 744, 918, 1128, 1380, 1681, 2039, 2464, 2968, 3563, 4264, 5088, 6054, 7184, 8503, 10040, 11827, 13901, 16304, 19082, 22289, 25986, 30240, 35128, 40736, 47161, 54512 (list; graph; refs; listen; history; internal format)
OFFSET

1,2

COMMENTS

It seems that a(n) is asymptotic to C*BesselI(0,2*sqrt(n)) where C is a constant C = 0.78... and BesselI(b,x) is the modified Bessel function of the first kind. Can someone prove this?

LINKS

Harry J. Smith, Table of n, a(n) for n=1,...,1000

Index entries for sequences related to Bessel functions or polynomials

FORMULA

a(1) = 1, a(n+1) = a(n) + ceil((a(1) + a(2) + ... + a(n))/n)

EXAMPLE

a(5) = a(4) + ceil((a(1)+a(2)+a(3)+a(4))/4) = 7 + ceil((1+2+4+7)/4) = 7 + floor(14/4) = 7 + 4 = 11

MAPLE

a[1] := 1: summe := 0: flip := 1: for j from 1 to 100 do: print (j, a[flip]); summe := summe + a[flip]: a[1-flip] := a[flip] + ceil(summe/j): flip := 1-flip: od:

MATHEMATICA

a[1] = 1; a[n_] := a[n] = a[n - 1] + Ceiling[ Sum[ a[i], {i, 1, n - 1} ]/(n - 1) ]; Table[ a[ n], {n, 1, 45} ]

PROG

(PARI) { for (n=1, 1000, if (n==1, s=0; a=1, s+=a; a+=ceil(s/(n - 1))); write("b065095.txt", n, " ", a) ) } [From Harry J. Smith (hjsmithh(AT)sbcglobal.net), Oct 06 2009]

CROSSREFS

Cf. A065094.

Sequence in context: A181120 A000601 A062433 * A005253 A129339 A196719

Adjacent sequences:  A065092 A065093 A065094 * A065096 A065097 A065098

KEYWORD

nonn,easy

AUTHOR

Ulrich Schimke (ulrschimke(AT)aol.com)

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Transforms | Puzzles | Hot | Classics
Recent Additions | More pages | Superseeker | Maintained by The OEIS Foundation Inc.

Content is available under The OEIS End-User License Agreement .

Last modified February 17 16:00 EST 2012. Contains 206050 sequences.