A228949 Coins left when packing boomerangs into n X n coins.

4, 3, 7, 13, 6, 13, 22, 9, 19, 31, 12, 25, 40, 15, 31, 49, 18, 37, 58, 21, 43, 67, 24, 49, 76, 27, 55, 85, 30, 61, 94, 33, 67, 103, 36, 73, 112, 39, 79, 121, 42, 85, 130, 45, 91, 139, 48, 97, 148, 51, 103, 157, 54, 109, 166, 57

Offset: 2

Author

Kival Ngaokrajang, Oct 05 2013

Keywords

• nonn
• easy

Comments

The coins left after packing boomerangs into n X n coins using the same rule as A229593. See illustration in links.

Links

• Kival Ngaokrajang, Illustration of initial terms
• Index entries for linear recurrences with constant coefficients, signature (0,0,2,0,0,-1).

Crossrefs

Cf. A229593 (Boomerangs), A229598 (Voids), A017209 (trisection), A008585 (trisection), A016921 (trisection).

Programs

Mathematica

LinearRecurrence[{0,0,2,0,0,-1},{4,3,7,13,6,13},80] (* Harvey P. Dale, Jan 19 2019 *)

Formula

G.f. -x^2*(-4-3*x-7*x^2-5*x^3+x^5) / ( (x-1)^2*(1+x+x^2)^2 ). - R. J. Mathar, Oct 16 2013