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URL: https://oeis.org/A287335

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A287335
Nonnegative numbers k such that 3*k + 2 is a cube.
3
2, 41, 170, 443, 914, 1637, 2666, 4055, 5858, 8129, 10922, 14291, 18290, 22973, 28394, 34607, 41666, 49625, 58538, 68459, 79442, 91541, 104810, 119303, 135074, 152177, 170666, 190595, 212018, 234989, 259562, 285791, 313730, 343433, 374954, 408347, 443666, 480965
OFFSET
1,1
COMMENTS
Corresponding cubes are listed in A016791.
Primes in the sequence: 2, 41, 443, 1637, 22973, 34607, 91541, 234989, ...
FORMULA
O.g.f.: x*(2 + 33*x + 18*x^2 + x^3)/(1 - x)^4.
E.g.f.: 1 - (1 - 3*x - 18*x^2 - 9*x^3)*exp(x).
a(n) = 9*n^3 - 9*n^2 + 3*n - 1.
a(n) = A131476(3*n-1) = A212069(3*n-1).
MATHEMATICA
Table[9 n^3 - 9 n^2 + 3 n - 1, {n, 0, 40}]
LinearRecurrence[{4, -6, 4, -1}, {2, 41, 170, 443}, 40] (* Harvey P. Dale, Aug 28 2021 *)
PROG
(Python) [9*n**3-9*n**2+3*n-1 for n in range(1, 40)]
(SageMath) [9*n^3-9*n^2+3*n-1 for n in (1..40)]
(Maxima) makelist(9*n^3-9*n^2+3*n-1, n, 1, 40);
(Magma) [9*n^3-9*n^2+3*n-1: n in [1..40]];
CROSSREFS
Subsequence of A047292.
Cf. A244728: nonnegative k such that 3*k is a cube.
Cf. A121628: nonnegative k such that 3*k + 1 is a cube.
Sequence in context: A007533 A088565 A090195 * A212837 A063271 A142160
KEYWORD
nonn,easy
AUTHOR
Bruno Berselli, May 23 2017
STATUS
approved