OFFSET
1,5
COMMENTS
Equals row sums of the eigentriangle A143809 of the Mobius transform;/Q and right border of A143809./Q A007554 = the eigensequence of the Mobius transform. [From Gary W. Adamson, Sep 01 2008]
REFERENCES
N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).
LINKS
Franklin T. Adams-Watters, Table of n, a(n) for n = 1..5000
M. Bernstein and N. J. A. Sloane, Some canonical sequences of integers, Linear Alg. Applications, 226-228 (1995), 57-72; erratum 320 (2000), 210. [Link to arXiv version]
M. Bernstein and N. J. A. Sloane, Some canonical sequences of integers, Linear Alg. Applications, 226-228 (1995), 57-72; erratum 320 (2000), 210. [Link to Lin. Alg. Applic. version together with omitted figures]
N. J. A. Sloane, Transforms
FORMULA
a(n+1) = Sum_{d|n} mu(n/d) * a(d).
G.f. A(x) satisfies: A(x) = x + x * Sum_{k>=1} mu(k) * A(x^k). - Ilya Gutkovskiy, Jul 01 2021
MATHEMATICA
a[n_] := a[n] = Sum[ MoebiusMu[ (n - 1)/d]*a[d], {d, Divisors[n - 1]}]; a[1] = 1; Table[a[n], {n, 1, 58}] (* Jean-François Alcover, Jan 04 2012, from formula *)
PROG
(Haskell)
import Data.List (genericIndex)
a007554 n = genericIndex a007554_list (n-1)
a007554_list = 1 : f 1 where
f x = (sum $ zipWith (*) (map a008683 divs)
(map a007554 $ reverse divs)) : f (x + 1)
where divs = a027750_row x
-- Reinhard Zumkeller, Mar 16 2013
CROSSREFS
KEYWORD
AUTHOR
STATUS
approved