The On-Line Encyclopedia of Integer Sequences (OEIS)

Revision History for A292504

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A292504

Number of orderless tree-factorizations of n.
(history; published version)

#15 by Alois P. Heinz at Sun Nov 18 19:26:30 EST 2018

STATUS

proposed

approved

#14 by Andrew Howroyd at Sun Nov 18 19:25:21 EST 2018

STATUS

editing

proposed

#13 by Andrew Howroyd at Sun Nov 18 19:25:18 EST 2018

CROSSREFS

Cf. A000311, A001055, A050336, A141268, A281118, A292505.

STATUS

proposed

editing

#12 by Andrew Howroyd at Sun Nov 18 19:24:02 EST 2018

STATUS

editing

proposed

#11 by Andrew Howroyd at Sun Nov 18 18:35:26 EST 2018

COMMENTS

a(n) depends only on the prime signature of n. - Andrew Howroyd, Nov 18 2018

FORMULA

a(p^n) = A141268(n) for prime p. - Andrew Howroyd, Nov 18 2018

PROG

(PARI) seq(n)={my(v=vector(n), w=vector(n)); w[1]=v[1]=1; for(k=2, n, w[k]=v[k]+1; forstep(j=n\k*k, k, -k, my(i=j, e=0); while(i%k==0, i/=k; e++; v[j] += binomial(e+w[k]-1, e)*v[i]))); w} \\ Andrew Howroyd, Nov 18 2018

STATUS

approved

editing

#10 by N. J. A. Sloane at Mon Oct 30 21:44:09 EDT 2017

STATUS

proposed

approved

#9 by Michael De Vlieger at Mon Oct 30 18:37:17 EDT 2017

STATUS

editing

proposed

#8 by Michael De Vlieger at Mon Oct 30 18:37:11 EDT 2017

LINKS

Michael De Vlieger, <a href="/A292504/a292504.txt">Records and indices of records</a>.

#7 by Michael De Vlieger at Mon Oct 30 18:33:14 EDT 2017

LINKS

Michael De Vlieger, <a href="/A292504/b292504.txt">Table of n, a(n) for n = 1..16384</a>

STATUS

approved

editing

#6 by N. J. A. Sloane at Sun Oct 01 00:06:28 EDT 2017

STATUS

proposed

approved