OFFSET
0,4
COMMENTS
The integers are displayed as in A277116, where the negative integers are depicted by using one more segment for the minus sign.
LINKS
Stefano Spezia, Table of n, a(n) for n = 0..4000
Stefano Spezia, Illustration for n = 7
Index entries for linear recurrences with constant coefficients, signature (0,1,1,1,4,2,1).
FORMULA
EXAMPLE
See illustration in Links section.
MATHEMATICA
P[x_]:=x^2+x^3+x^4+4x^5+2x^6+x^7; c[n_]:=Coefficient[Sum[P[x]^k, {k, Max[1, Ceiling[n/7]], Floor[n/2]}], x, n]; b[n_]:=c[n]-c[n-6]; (* A343315 *)
a[n_]:=If[n!=7, b[n]+b[n-1], 19]; Array[a, 40, 0]
CROSSREFS
KEYWORD
nonn,base,easy
AUTHOR
Stefano Spezia, Dec 31 2021
STATUS
approved