A138890 Non-Padovan numbers.

6, 8, 10, 11, 13, 14, 15, 17, 18, 19, 20, 22, 23, 24, 25, 26, 27, 29, 30, 31, 32, 33, 34, 35, 36, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63, 64, 66, 67, 68, 69, 70, 71, 72, 73, 74

Offset

1,1

Comments

Natural numbers that are not in the Padovan sequence A000931.

Links

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

Chai Wah Wu, Algorithms for complementary sequences, arXiv:2409.05844 [math.NT], 2024.

Mathematica

Complement[Range[0, Max[#]], #] &@ Union@ LinearRecurrence[{0, 1, 1}, {1, 0, 0}, 23] (* Michael De Vlieger, Sep 17 2024 *)

Prog

(Python)
def A138890(n):
    def f(x):
        if x<=1: return n+1
        a, b, c, d = 1, 1, 1, 0
        while c<=x:
            a, b, c = b, c, a+b
            d += 1
        return n+d-1
    m, k = n, f(n)
    while m != k: m, k = k, f(k)
    return m # Chai Wah Wu, Sep 10 2024

Crossrefs

Cf. A000931, A001690, A062289, A092460, A134816, A138836, A138888, A138891.

Sequence in context: A046344 A116366 A315849 * A189082 A171562 A018221

Adjacent sequences: A138887 A138888 A138889 * A138891 A138892 A138893

Keyword

easy,nonn

Author

Omar E. Pol, Apr 05 2008

Status

approved