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.

Showing 1-10 of 19 results. Next

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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Author

Keywords

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

A319797 Number T(n,k) of partitions of n into exactly k positive triangular numbers; triangle T(n,k), n>=0, 0<=k<=n, read by rows.

Original entry on oeis.org

1, 0, 1, 0, 0, 1, 0, 1, 0, 1, 0, 0, 1, 0, 1, 0, 0, 0, 1, 0, 1, 0, 1, 1, 0, 1, 0, 1, 0, 0, 1, 1, 0, 1, 0, 1, 0, 0, 0, 1, 1, 0, 1, 0, 1, 0, 0, 1, 1, 1, 1, 0, 1, 0, 1, 0, 1, 0, 1, 1, 1, 1, 0, 1, 0, 1, 0, 0, 1, 0, 1, 1, 1, 1, 0, 1, 0, 1, 0, 0, 1, 2, 1, 1, 1, 1, 1, 0, 1, 0, 1, 0, 0, 1, 1, 2, 1, 1, 1, 1, 1, 0, 1, 0, 1
Offset: 0

Views

Author

Alois P. Heinz, Sep 28 2018

Keywords

Comments

Equals A181506 when the first column is removed. - Georg Fischer, Jul 26 2023

Examples

			Triangle T(n,k) begins:
  1;
  0, 1;
  0, 0, 1;
  0, 1, 0, 1;
  0, 0, 1, 0, 1;
  0, 0, 0, 1, 0, 1;
  0, 1, 1, 0, 1, 0, 1;
  0, 0, 1, 1, 0, 1, 0, 1;
  0, 0, 0, 1, 1, 0, 1, 0, 1;
  0, 0, 1, 1, 1, 1, 0, 1, 0, 1;
  0, 1, 0, 1, 1, 1, 1, 0, 1, 0, 1;
  0, 0, 1, 0, 1, 1, 1, 1, 0, 1, 0, 1;
  0, 0, 1, 2, 1, 1, 1, 1, 1, 0, 1, 0, 1;
		

Crossrefs

Columns k=0-10 give: A000007, A010054 (for n>0), A052344, A063993, A319814, A319815, A319816, A319817, A319818, A319819, A319820.
Row sums give A007294.
T(2n,n) gives A319799.

Programs

  • Maple
    h:= proc(n) option remember; `if`(n<1, 0,
          `if`(issqr(8*n+1), n, h(n-1)))
        end:
    b:= proc(n, i) option remember; `if`(n=0 or i=1, x^n,
          b(n, h(i-1))+expand(x*b(n-i, h(min(n-i, i)))))
        end:
    T:= n-> (p-> seq(coeff(p, x, i), i=0..n))(b(n, h(n))):
    seq(T(n), n=0..20);
  • Mathematica
    h[n_] := h[n] = If[n < 1, 0, If[IntegerQ @ Sqrt[8*n + 1], n, h[n - 1]]];
    b[n_, i_] := b[n, i] = If[n == 0 || i == 1, x^n, b[n, h[i - 1]] + Expand[ x*b[n - i, h[Min[n - i, i]]]]];
    T[n_] := Table[Coefficient[#, x, i], {i, 0, n}]& @ b[n, h[n]];
    Table[T[n], {n, 0, 20}] // Flatten (* Jean-François Alcover, May 27 2019, after Alois P. Heinz *)

Formula

T(n,k) = [x^n y^k] 1/Product_{j>=1} (1-y*x^A000217(j)).

A319395 Number of partitions of n into exactly two positive Fibonacci numbers.

Original entry on oeis.org

0, 0, 1, 1, 2, 1, 2, 1, 1, 1, 2, 1, 0, 1, 1, 1, 2, 0, 1, 0, 0, 1, 1, 1, 1, 0, 2, 0, 0, 1, 0, 0, 0, 0, 1, 1, 1, 1, 0, 1, 0, 0, 2, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 0, 1, 0, 0, 1, 0, 0, 0, 0, 2, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0
Offset: 0

Views

Author

Alois P. Heinz, Sep 18 2018

Keywords

Crossrefs

Column k=2 of A319394.
Cf. A000045.

Programs

  • Maple
    h:= proc(n) option remember; `if`(n<1, 0, `if`((t->
          issqr(t+4) or issqr(t-4))(5*n^2), n, h(n-1)))
        end:
    b:= proc(n, i, t) option remember; `if`(n=0, 1, `if`(i<1 or
          t<1, 0, b(n, h(i-1), t)+b(n-i, h(min(n-i, i)), t-1)))
        end:
    a:= n-> (k-> b(n, h(n), k)-b(n, h(n), k-1))(2):
    seq(a(n), n=0..120);
  • Mathematica
    h[n_] := h[n] = If[n < 1, 0, If[Function[t, IntegerQ@Sqrt[t + 4] || IntegerQ@Sqrt[t - 4]][5 n^2], n, h[n - 1]]];
    b[n_, i_, t_] := b[n, i, t] = If[n == 0, 1, If[i < 1 || t < 1, 0, b[n, h[i - 1], t] + b[n - i, h[Min[n - i, i]], t - 1]]];
    a[n_] := With[{k = 2}, b[n, h[n], k] - b[n, h[n], k - 1]];
    a /@ Range[0, 120] (* Jean-François Alcover, Dec 07 2020, after Alois P. Heinz *)

Formula

a(n) = [x^n y^2] 1/Product_{j>=2} (1-y*x^A000045(j)).

A319397 Number of partitions of n into exactly four positive Fibonacci numbers.

Original entry on oeis.org

0, 0, 0, 0, 1, 1, 2, 2, 4, 3, 4, 4, 5, 4, 5, 4, 5, 5, 5, 5, 7, 4, 5, 4, 5, 5, 6, 5, 6, 5, 6, 5, 7, 4, 4, 3, 5, 5, 4, 6, 6, 5, 6, 4, 6, 6, 5, 5, 5, 5, 5, 4, 7, 4, 1, 4, 2, 4, 6, 3, 6, 5, 5, 6, 5, 6, 5, 3, 6, 3, 5, 6, 5, 6, 5, 2, 5, 3, 6, 5, 2, 5, 4, 3, 7, 1, 4
Offset: 0

Views

Author

Alois P. Heinz, Sep 18 2018

Keywords

Crossrefs

Column k=4 of A319394.
Cf. A000045.

Programs

  • Maple
    h:= proc(n) option remember; `if`(n<1, 0, `if`((t->
          issqr(t+4) or issqr(t-4))(5*n^2), n, h(n-1)))
        end:
    b:= proc(n, i, t) option remember; `if`(n=0, 1, `if`(i<1 or
          t<1, 0, b(n, h(i-1), t)+b(n-i, h(min(n-i, i)), t-1)))
        end:
    a:= n-> (k-> b(n, h(n), k)-b(n, h(n), k-1))(4):
    seq(a(n), n=0..120);
  • Mathematica
    h[n_] := h[n] = If[n < 1, 0, If[Function[t, IntegerQ@Sqrt[t + 4] || IntegerQ@Sqrt[t - 4]][5 n^2], n, h[n - 1]]];
    b[n_, i_, t_] := b[n, i, t] = If[n == 0, 1, If[i < 1 || t < 1, 0, b[n, h[i - 1], t] + b[n - i, h[Min[n - i, i]], t - 1]]];
    a[n_] := With[{k = 4}, b[n, h[n], k] - b[n, h[n], k - 1]];
    a /@ Range[0, 120] (* Jean-François Alcover, Dec 08 2020, after Alois P. Heinz *)

Formula

a(n) = [x^n y^4] 1/Product_{j>=2} (1-y*x^A000045(j)).

A359513 Number of partitions of n into at most 4 positive Fibonacci numbers (with a single type of 1).

Original entry on oeis.org

1, 1, 2, 3, 4, 5, 6, 6, 8, 7, 8, 8, 8, 8, 8, 8, 9, 8, 9, 8, 8, 8, 7, 8, 9, 7, 10, 8, 8, 9, 7, 8, 8, 4, 8, 5, 8, 9, 6, 10, 8, 6, 10, 6, 9, 8, 5, 9, 6, 6, 8, 4, 8, 4, 1, 8, 4, 7, 9, 5, 10, 7, 6, 10, 6, 8, 6, 3, 10, 5, 7, 9, 5, 8, 5, 2, 9, 4, 7, 6, 2, 8, 4, 3, 8, 1, 4, 1
Offset: 0

Views

Author

Ilya Gutkovskiy, Jan 03 2023

Keywords

Crossrefs

Programs

  • Maple
    h:= proc(n) option remember; `if`(n<1, 0, `if`((t->
          issqr(t+4) or issqr(t-4))(5*n^2), n, h(n-1)))
        end:
    b:= proc(n, i) option remember; `if`(n=0 or i=1, x^n,
          b(n, h(i-1))+expand(x*b(n-i, h(min(n-i, i)))))
        end:
    a:= n-> (p-> add(coeff(p, x, i), i=0..4))(b(n, h(n))):
    seq(a(n), n=0..87);  # Alois P. Heinz, Jan 03 2023
  • Mathematica
    h[n_] := h[n] = If[n < 1, 0, With[{t = 5 n^2}, If[IntegerQ @ Sqrt[t + 4] || IntegerQ @ Sqrt[t - 4], n, h[n - 1]]]];
    b[n_, i_] := b[n, i] = If[n == 0 || i == 1, x^n, b[n, h[i - 1]] + Expand[x*b[n - i, h[Min[n - i, i]]]]];
    a[n_] := Sum[Coefficient[#, x, i], {i, 0, 4}]&[b[n, h[n]]];
    Table[a[n], {n, 0, 87}] (* Jean-François Alcover, May 26 2023, after Alois P. Heinz *)

Formula

a(n) = Sum_{k=0..4} A319394(n,k). - Alois P. Heinz, Jan 03 2023

A319396 Number of partitions of n into exactly three positive Fibonacci numbers.

Original entry on oeis.org

0, 0, 0, 1, 1, 2, 2, 3, 2, 3, 2, 3, 3, 2, 2, 3, 2, 3, 3, 3, 1, 2, 1, 3, 3, 2, 2, 3, 2, 3, 1, 3, 1, 0, 2, 1, 2, 3, 2, 3, 2, 1, 2, 2, 3, 2, 0, 3, 1, 1, 3, 0, 1, 0, 0, 2, 1, 2, 2, 2, 3, 2, 1, 3, 1, 2, 1, 0, 2, 2, 2, 3, 0, 2, 0, 0, 3, 1, 1, 1, 0, 3, 0, 0, 1, 0, 0
Offset: 0

Views

Author

Alois P. Heinz, Sep 18 2018

Keywords

Crossrefs

Column k=3 of A319394.
Cf. A000045.

Programs

  • Maple
    h:= proc(n) option remember; `if`(n<1, 0, `if`((t->
          issqr(t+4) or issqr(t-4))(5*n^2), n, h(n-1)))
        end:
    b:= proc(n, i, t) option remember; `if`(n=0, 1, `if`(i<1 or
          t<1, 0, b(n, h(i-1), t)+b(n-i, h(min(n-i, i)), t-1)))
        end:
    a:= n-> (k-> b(n, h(n), k)-b(n, h(n), k-1))(3):
    seq(a(n), n=0..120);
  • Mathematica
    h[n_] := h[n] = If[n < 1, 0, If[Function[t, IntegerQ@Sqrt[t + 4] || IntegerQ@Sqrt[t - 4]][5 n^2], n, h[n - 1]]];
    b[n_, i_, t_] := b[n, i, t] = If[n == 0, 1, If[i < 1 || t < 1, 0, b[n, h[i - 1], t] + b[n - i, h[Min[n - i, i]], t - 1]]];
    a[n_] := With[{k = 3}, b[n, h[n], k] - b[n, h[n], k - 1]];
    a /@ Range[0, 120] (* Jean-François Alcover, Dec 07 2020, after Alois P. Heinz *)

Formula

a(n) = [x^n y^3] 1/Product_{j>=2} (1-y*x^A000045(j)).

A319398 Number of partitions of n into exactly five positive Fibonacci numbers.

Original entry on oeis.org

0, 0, 0, 0, 0, 1, 1, 2, 2, 4, 4, 5, 5, 7, 6, 7, 7, 8, 7, 9, 8, 10, 9, 9, 8, 11, 8, 10, 10, 11, 10, 11, 10, 13, 10, 11, 8, 10, 10, 10, 11, 12, 11, 11, 11, 13, 11, 12, 11, 12, 12, 11, 11, 13, 12, 10, 8, 10, 9, 9, 12, 11, 10, 13, 10, 14, 14, 11, 11, 11, 11, 13
Offset: 0

Views

Author

Alois P. Heinz, Sep 18 2018

Keywords

Crossrefs

Column k=5 of A319394.
Cf. A000045.

Programs

  • Maple
    h:= proc(n) option remember; `if`(n<1, 0, `if`((t->
          issqr(t+4) or issqr(t-4))(5*n^2), n, h(n-1)))
        end:
    b:= proc(n, i, t) option remember; `if`(n=0, 1, `if`(i<1 or
          t<1, 0, b(n, h(i-1), t)+b(n-i, h(min(n-i, i)), t-1)))
        end:
    a:= n-> (k-> b(n, h(n), k)-b(n, h(n), k-1))(5):
    seq(a(n), n=0..120);
  • Mathematica
    h[n_] := h[n] = If[n < 1, 0, If[Function[t, IntegerQ@Sqrt[t + 4] || IntegerQ@Sqrt[t - 4]][5 n^2], n, h[n - 1]]];
    b[n_, i_, t_] := b[n, i, t] = If[n == 0, 1, If[i < 1 || t < 1, 0, b[n, h[i - 1], t] + b[n - i, h[Min[n - i, i]], t - 1]]];
    a[n_] := With[{k = 5}, b[n, h[n], k] - b[n, h[n], k - 1]];
    a /@ Range[0, 120] (* Jean-François Alcover, Dec 08 2020 *)

Formula

a(n) = [x^n y^5] 1/Product_{j>=2} (1-y*x^A000045(j)).

A319399 Number of partitions of n into exactly six positive Fibonacci numbers.

Original entry on oeis.org

0, 0, 0, 0, 0, 0, 1, 1, 2, 2, 4, 4, 6, 6, 8, 8, 9, 9, 12, 10, 12, 12, 14, 13, 15, 13, 16, 15, 16, 15, 19, 16, 18, 18, 20, 18, 20, 17, 20, 17, 19, 19, 21, 21, 20, 20, 24, 21, 23, 21, 23, 22, 22, 23, 24, 23, 23, 20, 22, 21, 20, 21, 24, 22, 22, 23, 25, 25, 27, 23
Offset: 0

Views

Author

Alois P. Heinz, Sep 18 2018

Keywords

Crossrefs

Column k=6 of A319394.
Cf. A000045.

Programs

  • Maple
    h:= proc(n) option remember; `if`(n<1, 0, `if`((t->
          issqr(t+4) or issqr(t-4))(5*n^2), n, h(n-1)))
        end:
    b:= proc(n, i, t) option remember; `if`(n=0, 1, `if`(i<1 or
          t<1, 0, b(n, h(i-1), t)+b(n-i, h(min(n-i, i)), t-1)))
        end:
    a:= n-> (k-> b(n, h(n), k)-b(n, h(n), k-1))(6):
    seq(a(n), n=0..120);

Formula

a(n) = [x^n y^6] 1/Product_{j>=2} (1-y*x^A000045(j)).

A319400 Number of partitions of n into exactly seven positive Fibonacci numbers.

Original entry on oeis.org

0, 0, 0, 0, 0, 0, 0, 1, 1, 2, 2, 4, 4, 6, 7, 9, 9, 11, 11, 14, 14, 16, 15, 19, 17, 20, 20, 22, 21, 24, 22, 27, 25, 27, 26, 31, 28, 30, 29, 32, 29, 32, 30, 34, 33, 34, 34, 37, 36, 38, 36, 41, 37, 38, 39, 41, 41, 40, 39, 41, 38, 41, 38, 41, 42, 40, 41, 46, 43
Offset: 0

Views

Author

Alois P. Heinz, Sep 18 2018

Keywords

Crossrefs

Column k=7 of A319394.
Cf. A000045.

Programs

  • Maple
    h:= proc(n) option remember; `if`(n<1, 0, `if`((t->
          issqr(t+4) or issqr(t-4))(5*n^2), n, h(n-1)))
        end:
    b:= proc(n, i, t) option remember; `if`(n=0, 1, `if`(i<1 or
          t<1, 0, b(n, h(i-1), t)+b(n-i, h(min(n-i, i)), t-1)))
        end:
    a:= n-> (k-> b(n, h(n), k)-b(n, h(n), k-1))(7):
    seq(a(n), n=0..120);

Formula

a(n) = [x^n y^7] 1/Product_{j>=2} (1-y*x^A000045(j)).

A319401 Number of partitions of n into exactly eight positive Fibonacci numbers.

Original entry on oeis.org

0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 2, 2, 4, 4, 6, 7, 10, 10, 12, 13, 16, 16, 20, 19, 23, 22, 25, 25, 30, 28, 31, 31, 35, 34, 39, 36, 42, 40, 43, 42, 47, 44, 47, 46, 51, 48, 52, 51, 56, 55, 57, 56, 62, 59, 62, 60, 65, 64, 64, 65, 67, 64, 67, 65, 70, 67, 69, 68, 72
Offset: 0

Views

Author

Alois P. Heinz, Sep 18 2018

Keywords

Crossrefs

Column k=8 of A319394.
Cf. A000045.

Programs

  • Maple
    h:= proc(n) option remember; `if`(n<1, 0, `if`((t->
          issqr(t+4) or issqr(t-4))(5*n^2), n, h(n-1)))
        end:
    b:= proc(n, i, t) option remember; `if`(n=0, 1, `if`(i<1 or
          t<1, 0, b(n, h(i-1), t)+b(n-i, h(min(n-i, i)), t-1)))
        end:
    a:= n-> (k-> b(n, h(n), k)-b(n, h(n), k-1))(8):
    seq(a(n), n=0..120);

Formula

a(n) = [x^n y^8] 1/Product_{j>=2} (1-y*x^A000045(j)).
Showing 1-10 of 19 results. Next