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A358416
a(1) = 0 and a(n+1) > a(n) is the smallest integer such that a(n+1)^2-a(n)^2 is triangular.
1
0, 1, 2, 5, 14, 41, 46, 137, 410, 1229, 3686, 3818, 3982, 4015, 4036, 4091, 12272, 12320, 36959, 36991, 37328, 40505, 40615, 40856, 41542, 44222, 51913, 54032, 54785, 164354, 167686, 169769, 189742, 190225, 570674, 585136, 585161, 697507, 699542, 798592, 806618
OFFSET
1,3
COMMENTS
Square roots of A036449.
FORMULA
a(n) = sqrt(A036449(n)).
PROG
(Python)
from itertools import count, islice
from sympy import integer_nthroot
def A358416_gen(): # generator of terms
yield (a:=0)
for n in count(1):
if integer_nthroot(((b:=n**2)-a<<3)+1, 2)[1]:
yield n
a = b
A358416_list = list(islice(A358416_gen(), 41))
CROSSREFS
Cf. A036449.
Sequence in context: A159308 A163189 A243881 * A225691 A116846 A080558
KEYWORD
nonn
AUTHOR
Chai Wah Wu, Nov 14 2022
STATUS
approved