A048136 Tomahawk-nonconstructible n-gons.

11, 22, 23, 25, 29, 31, 33, 41, 43, 44, 46, 47, 49, 50, 53, 55, 58, 59, 61, 62, 66, 67, 69, 71, 75, 77, 79, 82, 83, 86, 87, 88, 89, 92, 93, 94, 98, 99, 100, 101, 103, 106, 107, 110, 113, 115, 116, 118, 121, 122, 123, 124, 125, 127, 129, 131, 132, 134

Offset

1,1

Links

Table of n, a(n) for n=1..58.

Andrew M. Gleason, Angle Trisection, the Heptagon and the Triskaidecagon, American Mathematical Monthly, 95 (1988), 185-194.

Formula

A122255(a(n)) = 0: complement of A122254. - Reinhard Zumkeller, Aug 29 2006

Prog

(Python)
from itertools import count, islice
from sympy import primefactors, totient
def A048136_gen(): # generator of terms
    yield from filter(lambda n: not set(primefactors(totient(n))) <= {2, 3}, count(3))
A048136_list = list(islice(A048136_gen(), 58)) # Chai Wah Wu, Apr 02 2025

Crossrefs

Cf. A005109, A048135, A122254, A122255.

Sequence in context: A231115 A040110 A140452 * A396015 A180054 A166713

Adjacent sequences: A048133 A048134 A048135 * A048137 A048138 A048139

Keyword

nonn

Author

David W. Wilson

Status

approved