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Revision History for A123707

(Underlined text is an addition; strikethrough text is a deletion.)

Showing all changes.
A123707 a(n) = Sum_{k=1..n} A123706(n,k)*2^(k-1).
(history; published version)
#9 by Susanna Cuyler at Thu Feb 06 14:50:14 EST 2020
STATUS

proposed

approved

#8 by Ilya Gutkovskiy at Thu Feb 06 14:12:17 EST 2020
STATUS

editing

proposed

#7 by Ilya Gutkovskiy at Thu Feb 06 13:27:19 EST 2020
FORMULA

G.f.: Sum_{k>=1} mu(k) * x^k * (1 - x^k) / (1 - 2*x^k). - Ilya Gutkovskiy, Feb 06 2020

MATHEMATICA

t[n_, k_] := If[Divisible[n, k], MoebiusMu[n/k], 0] - If[Divisible[n, k + 1], MoebiusMu[n/(k + 1)], 0]; Table[Sum[t[n, k]*2^(k - 1), {k, 1, n}], {n, 1, 50}] (* _G. C. GreublGreubel_, Oct 26 2017 *)

STATUS

approved

editing

#6 by Paul D. Hanna at Thu Oct 26 23:01:38 EDT 2017
STATUS

proposed

approved

#5 by G. C. Greubel at Thu Oct 26 21:28:36 EDT 2017
STATUS

editing

proposed

Discussion
Thu Oct 26 23:01
Paul D. Hanna: Thank you for the update!
#4 by G. C. Greubel at Thu Oct 26 21:28:29 EDT 2017
LINKS

G. C. Greubel, <a href="/A123707/b123707.txt">Table of n, a(n) for n = 1..1000</a>

MATHEMATICA

t[n_, k_] := If[Divisible[n, k], MoebiusMu[n/k], 0] - If[Divisible[n, k + 1], MoebiusMu[n/(k + 1)], 0]; Table[Sum[t[n, k]*2^(k - 1), {k, 1, n}], {n, 1, 50}] (* _G. C. Greubl_, Oct 26 2017 *)

STATUS

approved

editing

#3 by Russ Cox at Fri Mar 30 18:37:01 EDT 2012
AUTHOR

_Paul D. Hanna (pauldhanna(AT)juno.com), _, Oct 09 2006

Discussion
Fri Mar 30 18:37
OEIS Server: https://oeis.org/edit/global/213
#2 by N. J. A. Sloane at Sat Nov 10 03:00:00 EST 2007
KEYWORD

nonn,new

nonn

AUTHOR

Paul D . Hanna (pauldhanna(AT)juno.com), Oct 09 2006

#1 by N. J. A. Sloane at Wed Dec 06 03:00:00 EST 2006
NAME

a(n) = Sum_{k=1..n} A123706(n,k)*2^(k-1).

DATA

1, 0, 1, 3, 7, 14, 31, 60, 126, 248, 511, 1005, 2047, 4064, 8183, 16320, 32767, 65394, 131071, 261885, 524255, 1048064, 2097151, 4193220, 8388600, 16775168, 33554304, 67104765, 134217727, 268427002, 536870911, 1073725440, 2147483135

OFFSET

1,4

COMMENTS

Triangle A123706 is the matrix inverse of triangle A010766(n,k) = [n/k].

PROG

(PARI) {a(n)=sum(k=1, n, (matrix(n, n, r, c, if(r>=c, floor(r/c)))^-1)[n, k]*2^(k-1))}

CROSSREFS

Cf. A123706, A123708, A123709.

KEYWORD

nonn

AUTHOR

Paul D Hanna (pauldhanna(AT)juno.com), Oct 09 2006

STATUS

approved

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Last modified September 11 09:25 EDT 2024. Contains 375815 sequences. (Running on oeis4.)