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.

Previous Showing 21-28 of 28 results.

A219496 Number of representations of n as a sum of distinct elements of the generalized Fibonacci sequence beginning 8, 1, 9, 10, 19, 29, 48, ....

Original entry on oeis.org

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

Views

Author

Casey Mongoven, Nov 20 2012

Keywords

Crossrefs

Extensions

a(0)=1 from Alois P. Heinz, Sep 16 2015

A274262 Number of positive integers possessing exactly n Fibonacci representations (A000121).

Original entry on oeis.org

1, 2, 4, 6, 8, 12, 12, 18, 20, 24, 20, 44, 24, 36, 48, 54, 32, 76, 36, 88, 72, 60, 44, 156, 72, 72, 100, 132, 56, 208, 60, 162, 120, 96, 144, 316, 72, 108, 144, 312, 80, 312, 84, 220, 304, 132, 92, 540, 156, 280, 192, 264, 104, 460, 240, 468, 216, 168, 116, 116, 120, 180, 456, 486, 288, 520, 132, 352, 264, 624, 140
Offset: 1

Views

Author

Steven Finch, Jun 16 2016

Keywords

Examples

			Let phi denote the Euler totient.
The integer p^2*q has 8 multiplicative compositions:
  (p^2*q), p^2*q, q*p^2, p*(p*q), (p*q)*p, q*p*p, p*q*p, p*p*q
from which
  a(p^2*q) = 2*(3*phi(p^2)*phi(q) + 5*phi(p)^2*phi(q))
follows immediately.
		

Crossrefs

Formula

Let p, q, r be distinct primes and k be a positive integer.
If n = p^k then a(n) = 2*(p-1)*(2*p-1)^(k-1).
If n = p*q then a(n) = 6*(p-1)*(q-1).
If n = p^2*q then a(n) = 2*(p-1)*(8*p-5)*(q-1).
If n = p^3*q then a(n) = 2*(p-1)*(2*p-1)*(10*p-7)*(q-1).
If n = p^4*q then a(n) = 6*(p-1)*(2*p-1)^2*(4*p-3)*(q-1).
If n = p^2*q^2 then a(n) = 2*(p-1)*(q-1)*(26*p*q-18*p-18*q+13).
If n = p*q*r then a(n) = 26*(p-1)*(q-1)*(r-1).

A331922 Number of compositions (ordered partitions) of n into distinct Lucas numbers (beginning with 1).

Original entry on oeis.org

1, 1, 0, 1, 3, 2, 0, 3, 8, 0, 2, 9, 8, 0, 8, 32, 6, 0, 9, 32, 0, 8, 38, 30, 0, 32, 150, 0, 6, 33, 32, 0, 32, 158, 30, 0, 38, 174, 0, 30, 176, 150, 0, 150, 870, 24, 0, 33, 152, 0, 32, 182, 150, 0, 158, 894, 0, 30, 182, 174, 0, 174, 1014, 144, 0, 176, 990, 0, 150, 1014, 864
Offset: 0

Views

Author

Ilya Gutkovskiy, Feb 01 2020

Keywords

Examples

			a(7) = 3 because we have [7], [4, 3] and [3, 4].
		

Crossrefs

Cf. A000204, A003263, A054770 (positions of 0's), A067592, A067595, A218396, A288039.

A241952 Number of possible representations of n as a sum of distinct positive integers from the Fibonacci-type sequences 2,1,3,4,7,11,... and 0,2,2,4,6,10,16,... (A000032 and A118658).

Original entry on oeis.org

1, 1, 2, 2, 2, 3, 4, 3, 4, 6, 6, 6, 8, 8, 7, 10, 11, 11, 12, 14, 15, 15, 17, 17, 17, 19, 21, 22, 24, 25, 26, 28, 29, 30, 31, 34, 35, 36, 40, 40, 39, 43, 44, 44, 47, 50, 52, 53, 57, 58, 58, 61, 63, 65, 68, 70, 73, 76, 76, 80, 81, 82, 86, 88, 92, 93, 95, 99, 99, 101, 104, 105, 108, 111, 115, 118, 119, 124, 126, 127, 133, 134, 137, 142, 143, 149
Offset: 1

Views

Author

Casey Mongoven, May 03 2014

Keywords

Examples

			a(10) = 6 because 10 can be represented in 6 possible ways as a sum of integers in the set {1,2,3,4,6,7,10,11,16,...}: 10, 7+3, 7+2+1, 6+4, 6+3+1, 4+3+2+1.
		

Crossrefs

A241953 Number of possible representations of n as a sum of distinct positive integers from the Fibonacci-type sequences 2,1,3,4,7,11,... and 0,3,3,6,9,15,... (A000032 and A022086).

Original entry on oeis.org

1, 1, 2, 2, 2, 3, 4, 3, 5, 6, 6, 7, 8, 8, 9, 11, 10, 13, 13, 14, 16, 17, 16, 19, 21, 19, 24, 24, 25, 27, 30, 28, 32, 34, 33, 38, 37, 39, 42, 45, 42, 49, 48, 48, 55, 54, 55, 59, 63, 60, 68, 66, 68, 74, 74, 76, 81, 82, 81, 91, 86, 89, 97, 96, 97, 105, 104, 104, 114, 110, 113, 120, 120, 123, 130, 128, 131, 140, 137, 141, 149, 146
Offset: 1

Views

Author

Casey Mongoven, May 03 2014

Keywords

Examples

			a(10) = 6 because 10 can be represented in 6 possible ways as a sum of integers in the set {1,2,3,4,6,7,9,11,15,...}: 9+1, 7+3, 7+2+1, 6+4, 6+3+1, 4+3+2+1.
		

Crossrefs

A347349 a(n) is the smallest positive integer which can be represented as the sum of distinct Lucas numbers (A000032) in exactly n ways.

Original entry on oeis.org

1, 3, 7, 14, 21, 32, 50, 54, 83, 90, 130, 137, 144, 213, 220, 231, 347, 343, 372, 383, 376, 553, 864, 575, 618, 611, 911, 904, 897, 933, 991, 980, 1447, 987, 1461, 1454, 2261, 1577, 1508, 1584, 2337, 1595, 2355, 2344, 2427, 2554, 2351, 2438, 2550, 2579, 3853, 2590, 5951, 3806, 2583
Offset: 1

Views

Author

Ilya Gutkovskiy, Dec 19 2021

Keywords

Crossrefs

A357306 Number of compositions (ordered partitions) of n into distinct Lucas numbers (beginning at 2).

Original entry on oeis.org

1, 1, 1, 3, 3, 4, 8, 9, 8, 8, 32, 9, 14, 32, 38, 32, 36, 150, 33, 32, 32, 158, 38, 60, 174, 176, 150, 150, 870, 33, 56, 152, 182, 158, 180, 894, 182, 174, 174, 1014, 176, 294, 990, 1014, 870, 888, 5904, 153, 152, 152, 902, 182, 300, 1014, 1022, 894, 894
Offset: 0

Views

Author

Ilya Gutkovskiy, Sep 23 2022

Keywords

Crossrefs

A357427 Expansion of Product_{k>=0} 1 / (1 + x^Lucas(k)).

Original entry on oeis.org

1, -1, 0, -1, 1, 0, 1, -2, 2, -2, 2, -3, 3, -2, 4, -5, 4, -5, 5, -5, 6, -6, 8, -9, 8, -9, 9, -9, 11, -12, 13, -14, 14, -15, 15, -16, 20, -20, 20, -23, 23, -23, 25, -28, 31, -31, 32, -36, 36, -36, 41, -44, 45, -47, 49, -52, 54, -56, 62, -65, 65, -69, 72, -74, 79, -83, 87, -91
Offset: 0

Views

Author

Ilya Gutkovskiy, Sep 28 2022

Keywords

Comments

Convolution inverse of A067595.

Crossrefs

Programs

  • Mathematica
    nmax = 67; CoefficientList[Series[Product[1/(1 + x^LucasL[k]), {k, 0, 20}], {x, 0, nmax}], x]
Previous Showing 21-28 of 28 results.