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A382641
a(n) = round(c^n), where c is the supergolden ratio A092526.
0
1, 1, 2, 3, 5, 7, 10, 15, 21, 31, 46, 67, 98, 144, 211, 309, 453, 664, 973, 1426, 2090, 3063, 4489, 6579, 9642, 14131, 20710, 30352, 44483, 65193, 95545, 140028, 205221, 300766, 440794, 646015, 946781, 1387575, 2033590, 2980371, 4367946, 6401536, 9381907, 13749853
OFFSET
0,3
FORMULA
G.f.: (1 + x^2 + x^4 - x^8)/(1 - x - x^3).
a(n) = a(n-1) + a(n-3) for n>=9.
a(n) = round(((2/3)*cos((1/3)*arccos(29/2))+1/3)^n) = round(A092526^n).
a(n) = A001609(n) for n>=6.
MATHEMATICA
r = Root[x^3-x^2-1, 1]; Table[Round[r^i], {i, 0, 120 }]
CoefficientList[Series[(1+x^2+x^4-x^8)/(1-x-x^3), {x, 0, 120}], x]
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Jwalin Bhatt, Apr 01 2025
STATUS
approved