A090946 Non-Lucas numbers: complement of A000204.

0, 2, 5, 6, 8, 9, 10, 12, 13, 14, 15, 16, 17, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63, 64, 65, 66, 67, 68, 69, 70, 71, 72, 73, 74, 75, 77, 78, 79

Offset: 1

Author

N. J. A. Sloane, Feb 28 2004

Keywords

• nonn
• easy

Links

• G. C. Greubel, Table of n, a(n) for n = 1..10000

Crossrefs

Cf. A000032, A000204, A022801.

Programs

Maple

L[1]:=1: L[2]:=3: for n from 3 to 10 do L[n]:=L[n-1]+L[n-2] od: A:={seq(L[n],n=1..10)}: B:={seq(n,n=0..L[10])}: C:=B minus A; # Emeric Deutsch, Dec 14 2004

Mathematica

Complement[Range[0,100],LucasL[Range[10]]] (* Harvey P. Dale, Mar 21 2012 *)

Python

def A090946(n):
    if n == 1: return 0
    def f(x):
        if x<=2: return n
        a, b, c = 1, 3, 0
        while b<=x:
            a, b = b, a+b
            c += 1
        return n+c
    m, k = n, f(n)
    while m != k: m, k = k, f(k)
    return m # Chai Wah Wu, Sep 10 2024

Formula

a(n) = A057854(n-2), n>2. - R. J. Mathar, Jan 29 2019

Extensions

More terms from Emeric Deutsch, Dec 14 2004

Offset corrected by Michel Marcus, Aug 15 2017