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!)
A328967 a(n+1) = 1 - Sum_{k=1..n} a(floor(n/k)). 0
1, 0, 0, -1, 0, -2, 0, -3, 1, -4, 0, -5, 3, -6, 1, -8, 5, -9, 3, -10, 8, -13, 4, -14, 15, -16, 7, -21, 15, -22, 14, -23, 27, -28, 14, -32, 32, -33, 20, -42, 41, -43, 32, -44, 50, -57, 33, -58, 71, -61, 46, -75, 70, -76, 59, -82, 98, -95, 62, -96, 117, -97, 81, -122, 131 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,6

LINKS

Table of n, a(n) for n=1..65.

FORMULA

G.f. A(x) satisfies: A(x) = (x/(1 - x)) * (1 - Sum_{k>=1} (1 - x^k) * A(x^k)).

MATHEMATICA

a[n_] := a[n] = 1 - Sum[a[Floor[(n - 1)/k]], {k, 1, n - 1}]; Table[a[n], {n, 1, 65}]

A281487[1] = 1; A281487[n_] := A281487[n] = -Sum[A281487[d], {d, Divisors[n - 1]}]; Table[A281487[n], {n, 1, 65}] // Accumulate

CROSSREFS

Cf. A003318, A281487 (first differences).

Sequence in context: A249122 A135157 A135156 * A277707 A316524 A194549

Adjacent sequences:  A328964 A328965 A328966 * A328968 A328969 A328970

KEYWORD

sign

AUTHOR

Ilya Gutkovskiy, Feb 25 2020

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 April 5 20:19 EDT 2020. Contains 333260 sequences. (Running on oeis4.)