OFFSET
0,2
COMMENTS
Related to the primitive Pythagorean triple [15, 8, 17].
LINKS
Index entries for linear recurrences with constant coefficients, signature (3, -3, 1).
FORMULA
a(n) = (23*n^2 + 23*n)/2 = 23*n*(n+1)/2 = 23*A000217(n).
a(0)=0, a(1)=23, a(2)=69, a(n)=3*a(n-1)-3*a(n-2)+a(n-3). - Harvey P. Dale, Aug 28 2012
MATHEMATICA
23*Accumulate[Range[0, 40]] (* or *) LinearRecurrence[{3, -3, 1}, {0, 23, 69}, 50] (* Harvey P. Dale, Aug 28 2012 *)
PROG
(PARI) a(n)=23*n*(n+1)/2 \\ Charles R Greathouse IV, Jun 17 2017
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Omar E. Pol, Sep 12 2011
STATUS
approved