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A359502
a(n) = a(n-2)^2 + a(n-1) + 1 for n >= 2 with a(0) = 0 and a(1) = 1.
0
0, 1, 2, 4, 9, 26, 108, 785, 12450, 628676, 155631177, 395389144154, 24221458643549484, 156332599536291235925201, 586679058977510608947573592591458, 24439881677774993432884951095586547256059481860
OFFSET
0,3
MATHEMATICA
a[0] = 0; a[1] = 1; a[n_] := a[n] = a[n - 2]^2 + a[n - 1] + 1; Array[a, 16, 0] (* Amiram Eldar, Jan 05 2023 *)
PROG
(Python)
# a generator
def agen_q():
a, b = 0, 1
while 1:
yield a
a, b = b, (a * a) + b + 1
f = agen_q(); print([next(f) for _ in range(20)])
CROSSREFS
Sequence in context: A114957 A002773 A112706 * A110138 A148085 A003320
KEYWORD
nonn
AUTHOR
Andrew Wall, Jan 03 2023
STATUS
approved