The On-Line Encyclopedia of Integer Sequences (OEIS)

Revision History for A263897 (Bold, blue-underlined text is an addition; faded, red-underlined text is a ~~deletion~~.)
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A263897

Number of anagram compositions of 2n that can be formed from the compositions of n.
(history; published version)

#42 by Alois P. Heinz at Sun May 03 13:45:37 EDT 2020

STATUS

reviewed

approved

#41 by Michel Marcus at Sun May 03 12:52:25 EDT 2020

STATUS

proposed

reviewed

#40 by F. Chapoton at Sun May 03 12:26:00 EDT 2020

STATUS

editing

proposed

#39 by F. Chapoton at Sun May 03 12:25:50 EDT 2020

PROG

def b(n, i, p): return f(p)**2 if n==0 else 0 if i<1 else sum([b(n - i*j, i - 1, p + j)//f(j)**2 for j in range(n//i + 1)])

print map([a, (n) for n in range(36)]) # Indranil Ghosh, Aug 18 2017, after Maple code

STATUS

approved

editing

Discussion

Sun May 03

12:26

F. Chapoton: adapt py code to python3

#38 by N. J. A. Sloane at Sat Dec 07 12:33:53 EST 2019

PROG

print map(a, xrangerange(36)) # Indranil Ghosh, Aug 18 2017, after Maple code

Discussion

Sat Dec 07

12:33

OEIS Server: https://oeis.org/edit/global/2838

#37 by N. J. A. Sloane at Sat Dec 07 12:18:28 EST 2019

PROG

def b(n, i, p): return f(p)**2 if n==0 else 0 if i<1 else sum([b(n - i*j, i - 1, p + j)/f(j)**2 for j in xrangerange(n/i + 1)])

Discussion

Sat Dec 07

12:18

OEIS Server: https://oeis.org/edit/global/2837

#36 by Alois P. Heinz at Fri Aug 18 15:56:03 EDT 2017

STATUS

proposed

approved

#35 by Indranil Ghosh at Fri Aug 18 15:03:25 EDT 2017

STATUS

editing

proposed

#34 by Indranil Ghosh at Fri Aug 18 15:03:16 EDT 2017

PROG

(Python)

from sympy.core.cache import cacheit

from sympy import factorial as f

@cacheit

def b(n, i, p): return f(p)**2 if n==0 else 0 if i<1 else sum([b(n - i*j, i - 1, p + j)/f(j)**2 for j in xrange(n/i + 1)])

def a(n): return b(n, n, 0)

print map(a, xrange(36)) # Indranil Ghosh, Aug 18 2017, after Maple code

STATUS

approved

editing

#33 by Alois P. Heinz at Fri Aug 18 05:19:38 EDT 2017

STATUS

proposed

approved