OFFSET
0,3
COMMENTS
For a guide to related sequences, see A211795.
Also the number of (w,x,y) with all terms in {0,...,n-1} and |w-x| < |x-y|, see A212959. - Clark Kimberling, Jun 02 2012
LINKS
Index entries for linear recurrences with constant coefficients, signature (3,-2,-2,3,-1).
FORMULA
a(n) = 2*A019298(n-1) for n>=1.
a(n) = 3*a(n-1) - 2*a(n-2) - 2*a(n-3) + 3*a(n-4) - a(n-5).
G.f.: (2*x^2 + 2*x^3 + 2*x^4)/(1 - 3*x + 2*x^2 + 2*x^3 - 3*x^4 + x^5).
a(n) + A212962(n-1) = n^3. - _Clark Kimberling, Jun 02 2012
a(n) = (2*n^3 - 3*n^2 + 2*n - (n mod 2))/4. - Ayoub Saber Rguez, Sep 02 2021
MATHEMATICA
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Clark Kimberling, May 24 2012
STATUS
approved