A396072 Numbers not of the form Sum_{k=1..m} floor(m/k^2).

4, 9, 11, 15, 20, 21, 24, 27, 32, 34, 37, 39, 44, 45, 50, 51, 52, 57, 62, 64, 68, 69, 71, 73, 76, 79, 82, 87, 91, 93, 94, 95, 100, 105, 106, 107, 111, 113, 118, 119, 121, 122, 126, 131, 134, 137, 142, 143, 146, 148, 150, 151, 152, 157, 162, 163, 164, 169, 170

Offset

1,1

Comments

Complement of A013936.

Links

Chai Wah Wu, Table of n, a(n) for n = 1..10000

Mathematica

Complement[Range[Last[#]], #] &@ Table[Sum[Floor[n/k^2], {k, n}], {n, 120}] (* Michael De Vlieger, May 16 2026 *)

Prog

(Python)
from itertools import count, islice
# uses Python function in A013936
def A396072_gen(): # generator of terms
    c = 0
    for i in count(0):
        if (m:=A013936(i))!=i+c:
            for j in range(i+c, m):
                yield j
            c = m-i
A396072_list = list(islice(A396072_gen(), 60))

Crossrefs

Cf. A013936, A396046, A396056.

Sequence in context: A243178 A312834 A312835 * A387864 A250176 A312836

Adjacent sequences: A396068 A396069 A396070 * A396073 A396074 A396075

Keyword

nonn

Author

Chai Wah Wu, May 15 2026

Status

approved