OFFSET
1,2
COMMENTS
This sequence lists all positive integers n such that 2*n - 3 is a cube. Only for first term 2*n - 3 generates a negative cube that is -1. - Altug Alkan, Apr 15 2016
LINKS
Index entries for linear recurrences with constant coefficients, signature (4, -6, 4, -1).
FORMULA
a(n+1) = A050492(n)+1.
G.f.: x*(1 - 2*x + 13*x^2 + 12*x^3)/(1 - x)^4. - Ilya Gutkovskiy, Apr 15 2016
MATHEMATICA
Table[((2 n - 1)^3 + 3)/2, {n, 0, 41}] (* or *)
Rest@ CoefficientList[Series[x (1 - 2 x + 13 x^2 + 12 x^3)/(1 - x)^4, {x, 0, 42}], x] (* Michael De Vlieger, Apr 16 2016 *)
LinearRecurrence[{4, -6, 4, -1}, {1, 2, 15, 64}, 70] (* Harvey P. Dale, Jun 06 2022 *)
PROG
(Magma) [((2*n-1)^3+3)/2: n in [0..40]];
(PARI) lista(nn) = for(n=0, nn, print1(((2*n-1)^3+3)/2, ", ")); \\ Altug Alkan, Apr 15 2016
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Juri-Stepan Gerasimov, Apr 15 2016
STATUS
approved