VOOZH about

URL: https://oeis.org/A240562

⇱ A240562 - OEIS

login
A240562
Integers whose squares are in A000073 (tribonacci numbers).
0
0, 1, 2, 9, 56, 103
OFFSET
1,3
COMMENTS
a(6) > 10^7. - Tom Edgar, Apr 26 2014
Is this sequence finite?
No more terms < 10^19300. I conjecture that the sequence is finite. - Manfred Scheucher, Aug 17 2015
EXAMPLE
9^2 = 81 is in the tribonacci sequence, so 9 is a term.
MATHEMATICA
Select[Sqrt[#]&/@LinearRecurrence[{1, 1, 1}, {0, 0, 1}, 200], IntegerQ]// Union (* Harvey P. Dale, Aug 16 2021 *)
PROG
(SageMath)
def tribs():
a, b, c = 0, 0, 1
while True:
yield a
a, b, c = b, c, a+b+c
for n in tribs():
m = sqrt(n)
if m.is_integer():
print(m) # Manfred Scheucher, Aug 17 2015
CROSSREFS
Cf. A000073 (tribonacci numbers), A128911 (the corresponding squares).
Sequence in context: A241457 A229208 A154749 * A091108 A179405 A081004
KEYWORD
nonn,more,hard
AUTHOR
J. Lowell, Apr 16 2014
EXTENSIONS
Zero prepended by Harvey P. Dale, Aug 16 2021
STATUS
approved