A344000 Indices k such that A011772(k) is even.

3, 5, 7, 9, 10, 11, 12, 13, 17, 18, 19, 21, 23, 25, 26, 27, 29, 31, 34, 35, 36, 37, 39, 41, 42, 43, 44, 47, 48, 49, 50, 53, 55, 56, 57, 58, 59, 61, 67, 68, 70, 71, 73, 74, 75, 76, 78, 79, 80, 81, 82, 83, 84, 85, 88, 89, 93, 97, 98, 99, 100, 101, 103, 104, 105, 106, 107, 108, 109, 110, 111, 113, 114, 117, 119

Offset

1,1

Links

N. J. A. Sloane, Table of n, a(n) for n = 1..9196

Prog

(Python)
from sympy.ntheory.modular import crt
from sympy import factorint
from math import prod
from itertools import count, islice, combinations
def A344000_gen(): # generator of terms
    for n in count(1):
        plist = tuple(p**q for p, q in factorint(2*n).items())
        if len(plist) > 1 and min(min(crt((m, 2*n//m), (0, -1))[0], crt((2*n//m, m), (0, -1))[0]) for m in (prod(d) for l in range(1, len(plist)//2+1) for d in combinations(plist, l))) & 1 == 0:
            yield n
A344000_list = list(islice(A344000_gen(), 40)) # Chai Wah Wu, Jun 15 2022

Crossrefs

Cf. A011772, A343999, A344001.

Sequence in context: A194377 A344449 A258432 * A128938 A215138 A367539

Adjacent sequences: A343997 A343998 A343999 * A344001 A344002 A344003

Keyword

nonn

Author

N. J. A. Sloane, Jun 01 2021

Status

approved