OFFSET
1,2
LINKS
Index entries for linear recurrences with constant coefficients, signature (35, -35, 1).
FORMULA
a(n) = A164055(n)-1.
a(n) = 35*a(n-1) -35*a(n-2) +a(n-3) = 9*A001110(n-1). G.f.: 9*x^2*(1+x)/((1-x)*(x^2-34*x+1)). [R. J. Mathar, Oct 21 2009]
EXAMPLE
324=18^2 is a perfect square and 325=A000217(25) is a triangular number. Therefore 324 is in this sequence.
MATHEMATICA
LinearRecurrence[{35, -35, 1}, {0, 9, 324}, 20] (* Harvey P. Dale, Oct 24 2023 *)
CROSSREFS
KEYWORD
nonn
AUTHOR
Tanya Khovanova & Alexey Radul, Aug 09 2009
EXTENSIONS
Comments turned into formulas. - R. J. Mathar, Oct 21 2009
STATUS
approved