cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

A003107 Number of partitions of n into Fibonacci parts (with a single type of 1).

Original entry on oeis.org

1, 1, 2, 3, 4, 6, 8, 10, 14, 17, 22, 27, 33, 41, 49, 59, 71, 83, 99, 115, 134, 157, 180, 208, 239, 272, 312, 353, 400, 453, 509, 573, 642, 717, 803, 892, 993, 1102, 1219, 1350, 1489, 1640, 1808, 1983, 2178, 2386, 2609, 2854, 3113, 3393, 3697, 4017, 4367, 4737
Offset: 0

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Comments

The partitions allow repeated items but the order of items is immaterial (1+2=2+1). - Ron Knott, Oct 22 2003
A098641(n) = a(A000045(n)). - Reinhard Zumkeller, Apr 24 2005

Examples

			a(4) = 4 since the 4 partitions of 4 using only Fibonacci numbers, repetitions allowed, are 1+1+1+1, 2+2, 2+1+1, 3+1.
		

References

  • N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).

Crossrefs

Cf. A007000, A005092, A028290 (where the only Fibonacci numbers allowed are 1, 2, 3, 5 and 8).
Row sums of A319394.

Programs

  • Haskell
    import Data.MemoCombinators (memo2, integral)
    a003107 n = a003107_list !! n
    a003107_list = map (p' 2) [0..] where
       p' = memo2 integral integral p
       p _ 0 = 1
       p k m | m < fib   = 0
             | otherwise = p' k (m - fib) + p' (k + 1) m where fib = a000045 k
    -- Reinhard Zumkeller, Dec 09 2015
    
  • Maple
    F:= combinat[fibonacci]:
    b:= proc(n, i) option remember; `if`(n=0, 1, `if`(i<2, 0,
           b(n, i-1)+`if`(F(i)>n, 0, b(n-F(i), i))))
        end:
    a:= proc(n) local j; for j from ilog[(1+sqrt(5))/2](n+1)
           while F(j+1)<=n do od; b(n, j)
        end:
    seq(a(n), n=0..100);  # Alois P. Heinz, Jul 11 2013
  • Mathematica
    CoefficientList[ Series[1/ Product[1 - x^Fibonacci[i], {i, 2, 21}], {x, 0, 53}], x] (* Robert G. Wilson v, Mar 28 2006 *)
    nmax = 53;
    s = Table[Fibonacci[n], {n, nmax}];
    Table[Count[IntegerPartitions@n, x_ /; SubsetQ[s, x]], {n, 0, nmax}] (* Robert Price, Jul 31 2020 *)
    F = Fibonacci;
    b[n_, i_] := b[n, i] = If[n == 0, 1, If[i < 2, 0,
         b[n, i - 1] + If[F[i] > n, 0, b[n - F[i], i]]]];
    a[n_] := Module[{j}, For[j = Floor@Log[(1+Sqrt[5])/2, n+1],
         F[j + 1] <= n, j++]; b[n, j]];
    a /@ Range[0, 100] (* Jean-François Alcover, May 21 2021, after Alois P. Heinz *)
  • PARI
    f(x,y,z)=if(xCharles R Greathouse IV, Dec 14 2015

Formula

a(n) = (1/n)*Sum_{k=1..n} A005092(k)*a(n-k), n > 1, a(0)=1. - Vladeta Jovovic, Jan 21 2002
G.f.: Product_{i>=2} 1/(1-x^fibonacci(i)). - Ron Knott, Oct 22 2003
a(n) = f(n,1,1) with f(x,y,z) = if xReinhard Zumkeller, Nov 11 2009
G.f.: 1 + Sum_{i>=2} x^Fibonacci(i) / Product_{j=2..i} (1 - x^Fibonacci(j)). - Ilya Gutkovskiy, May 07 2017

Extensions

More terms from Vladeta Jovovic, Jan 21 2002