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Revision History for A115625 (Underlined text is an addition; strikethrough text is a deletion.)

Showing entries 1-10 | older changes
A115625 Number of partitions of {1,...,n} into block sizes a power of 2.
(history; published version)
#12 by Alois P. Heinz at Fri Apr 21 14:31:10 EDT 2023
STATUS

editing

approved

#11 by Alois P. Heinz at Fri Apr 21 14:31:08 EDT 2023
MAPLE

# second Maple program:

a:= proc(n) option remember; `if`(n=0, 1, add((j->

a(n-j)*binomial(n-1, j-1))(2^i), i=0..ilog2(n)))

end:

seq(a(n), n=0..30); # Alois P. Heinz, Apr 21 2023

STATUS

approved

editing

#10 by Alois P. Heinz at Thu Oct 29 08:05:59 EDT 2015
STATUS

proposed

approved

#9 by Jean-François Alcover at Thu Oct 29 07:29:41 EDT 2015
STATUS

editing

proposed

#8 by Jean-François Alcover at Thu Oct 29 07:29:34 EDT 2015
MATHEMATICA

multinomial[n_, k_List] := n!/Times @@ (k!); !); b[n_, i_] := b[n, i] = If[n == 0, 1, If[i<1, 0, Sum[multinomial[n, Join[{n-i*j}, Array[i&, j]]]/j!*b[n - i*j, i/2], {j, 0, n/i}]]]; a[n_] := b[n, 2^Floor[Log[2, n]]]; Table[a[n], {n, 0, 30}] (* _Jean-François Alcover_, Oct 29 2015, after _Alois P. Heinz_ *)

b[n_, i_] :=

b[n, i] =

If[n == 0, 1,

If[i < 1, 0,

Sum[multinomial[n, Join[{ n - i*j}, Array[i &, j]]]/j!*

b[n - i*j, i/2], {j, 0, n/i}]]] ;

a[n_] := b[n, 2^Floor[Log[2, n]]]; Table[a[n], {n, 0, 30}]

#7 by Jean-François Alcover at Thu Oct 29 07:27:07 EDT 2015
MATHEMATICA

multinomial[n_, k_List] := n!/Times @@ (k!);

b[n_, i_] :=

b[n, i] =

If[n == 0, 1,

If[i < 1, 0,

Sum[multinomial[n, Join[{ n - i*j}, Array[i &, j]]]/j!*

b[n - i*j, i/2], {j, 0, n/i}]]] ;

a[n_] := b[n, 2^Floor[Log[2, n]]]; Table[a[n], {n, 0, 30}]

STATUS

approved

editing

#6 by Alois P. Heinz at Thu Sep 17 16:16:06 EDT 2015
STATUS

editing

approved

#5 by Alois P. Heinz at Thu Sep 17 16:16:03 EDT 2015
LINKS

Alois P. Heinz, <a href="/A115625/b115625.txt">Table of n, a(n) for n = 0..604</a>

#4 by Alois P. Heinz at Thu Sep 17 16:15:47 EDT 2015
MAPLE

with(combinat):

b:= proc(n, i) option remember; `if`(n=0, 1,

`if`(i<1, 0, add(multinomial(n, n-i*j, i$j)/j!*

b(n-i*j, i/2), j=0..n/i)))

end:

a:= n-> b(n, 2^ilog2(n)):

seq(a(n), n=0..30); # Alois P. Heinz, Sep 17 2015

#3 by Alois P. Heinz at Thu Sep 17 16:12:30 EDT 2015
DATA

1, 1, 2, 4, 11, 31, 106, 372, 1500, 6220, 28696, 136016, 702802, 3727946, 21253324, 124231096, 772458367, 4918962479, 33061095118, 227303570524, 1639389365201, 12082068856285, 92951844299150, 729991789222972, 5960617085224012, 49637008114202876

STATUS

approved

editing

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Last modified August 29 11:12 EDT 2024. Contains 375512 sequences. (Running on oeis4.)