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A072214 Number of partitions of Fibonacci(n). 5
1, 1, 2, 3, 7, 22, 101, 792, 12310, 451276, 49995925, 22540654445, 60806135438329, 1596675274490756791, 758949605954969709105721, 14362612091531863067120268402228, 29498346711208035625096160181520548669694, 23537552807178094028466621551669121053281242290608650 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,3

COMMENTS

Also number of partitions of F(n+2) whose highest term is F(n+1) ( or, which is the same, whose number of terms is F(n+1)). - Philippe LALLOUET (philip.lallouet(AT)wanadoo.fr), Sep 14 2007

Divide the set of partitions P(i,j) in two subsets : 1) Partitions containing at least one term 1; Deleting a term 1, we prove that their number is P(i-1,j-1) 2). Subtracting 1 from each term of the other partitions we prove that their number is P(i-j,j) Hence P(i,j) - P(i-1,j-1) = P(i-j,j) Replacing successively in this formula i by i-1 and j by j-1 and summing all these equalities we get, if j>= floor((i+1)/2) P(i,j)=sum ({k,1,j}P(i-j;k))= A000041(i-j) As for i=F(n+2) and j=F(n+1) the condition is satisfied : P(F(n+2),F(n+1)) = P (F(n+2),F(n+1)= A000041(n) = 1072214(n). - Philippe LALLOUET (philip.lallouet(AT)wanadoo.fr), Sep 14 2007

LINKS

Seiichi Manyama, Table of n, a(n) for n = 1..26

FORMULA

Let P(i,j) denote the number of partitions of i whose highest term is j A072214(n) = A000041(F(n)) = P(F(n+2),F(n+1)) - Philippe LALLOUET (philip.lallouet(AT)wanadoo.fr), Sep 14 2007

a(n) = A000041(A000045(n)). - Michel Marcus, May 09 2016

a(n) = [x^Fibonacci(n)] Product_{k>=1} 1/(1 - x^k). - Ilya Gutkovskiy, Jun 08 2017

EXAMPLE

F(5) = 5, F(4) = 3: 5 = 3+2 = 3+1+1 (or 5 = 3+1+1 = 2+2+1), then P(5,3) = 2 = A000041(2) = A000041(F(3)) = A072214(3).

MATHEMATICA

Table[PartitionsP[Fibonacci[n]], {n, 1, 17}]

PROG

(Haskell)

a072214 = a000041 . a000045 . (+ 1)  -- Reinhard Zumkeller, Dec 09 2015

(MAGMA) [NumberOfPartitions(Fibonacci(n)): n in [1..18]]; // Vincenzo Librandi May 09 2016

(PARI) a(n) = numbpart(fibonacci(n)); \\ Michel Marcus, May 09 2016

(Python)

from sympy import npartitions as p, fibonacci as f

def a(n): return p(f(n)) # Indranil Ghosh, Jun 08 2017

CROSSREFS

Cf. A000041, A000045.

Sequence in context: A077210 A324620 A151908 * A233535 A007660 A158055

Adjacent sequences:  A072211 A072212 A072213 * A072215 A072216 A072217

KEYWORD

nonn

AUTHOR

Jeff Burch, Jul 03 2002

EXTENSIONS

Edited by Robert G. Wilson v, Jul 06 2002

a(18) by Vincenzo Librandi, May 09 2016

STATUS

approved

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Last modified May 28 13:20 EDT 2020. Contains 334683 sequences. (Running on oeis4.)