OFFSET
0,2
COMMENTS
a(n) is a fifth-order linear recurrence whose main interest is that it is related to (at least) eight other sequences (see the formula section).
LINKS
Index entries for linear recurrences with constant coefficients, signature (1,2,-2,-1,1).
FORMULA
MATHEMATICA
a[n_] := (n + 1)(n - 1 + Mod[n, 2]); Table[a[n], {n, 0, 50}]
PROG
(PARI) a(n)=if(n%2, n, n-1)*(n+1) \\ Charles R Greathouse IV, Jul 14 2017
CROSSREFS
KEYWORD
sign,easy
AUTHOR
Jean-François Alcover and Paul Curtz, Jul 14 2017
STATUS
approved