OFFSET
0,2
COMMENTS
A diagonal of the square array A223968.
LINKS
Michael De Vlieger, Table of n, a(n) for n = 0..1766
László Németh and László Szalay, Sequences Involving Square Zig-Zag Shapes, J. Int. Seq., Vol. 24 (2021), Article 21.5.2.
Index entries for linear recurrences with constant coefficients, signature (9,-28,35,-15,1).
FORMULA
MATHEMATICA
LinearRecurrence[{9, -28, 35, -15, 1}, {1, 5, 20, 75, 275}, 26] (* Michael De Vlieger, Aug 05 2021 *)
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Philippe Deléham, Apr 06 2013
STATUS
approved