A065187 "Greedy Dragons" permutation of the natural numbers, inverse of A065186.

1, 4, 2, 5, 3, 6, 9, 7, 10, 8, 11, 14, 12, 15, 13, 16, 19, 17, 20, 18, 21, 24, 22, 25, 23, 26, 29, 27, 30, 28, 31, 34, 32, 35, 33, 36, 39, 37, 40, 38, 41, 44, 42, 45, 43, 46, 49, 47, 50, 48, 51, 54, 52, 55, 53, 56, 59, 57, 60, 58, 61, 64, 62, 65, 63, 66, 69, 67, 70, 68, 71, 74

Offset

1,2

Links

Michael De Vlieger, Table of n, a(n) for n = 1..10000

Index entries for sequences that are permutations of the natural numbers

Formula

From Chai Wah Wu, Oct 23 2017: (Start)

a(1) = 1, a(2) = 4, a(3) = 2, a(4) = 5, a(5) = 3; for n > 5, a(n) = a(n-5) + 5.

a(n) = a(n-1) + a(n-5) - a(n-6) for n > 6.

G.f.: x*(2*x^5 - 2*x^4 + 3*x^3 - 2*x^2 + 3*x + 1)/((x - 1)*(x^5 - 1)). (End)

Mathematica

Rest@ CoefficientList[Series[x (2 x^5 - 2 x^4 + 3 x^3 - 2 x^2 + 3 x + 1)/((x - 1) (x^5 - 1)), {x, 0, 72}], x] (* Michael De Vlieger, Oct 23 2017 *)

Crossrefs

Sequence in context: A309567 A243855 A267185 * A185511 A199855 A127914

Adjacent sequences: A065184 A065185 A065186 * A065188 A065189 A065190

Keyword

nonn

Author

Antti Karttunen, Oct 19 2001

Status

approved