A106251 Expansion of (1-x+x^2+x^3+x^5)/(1-x-x^6+x^7).

1, 0, 1, 2, 2, 3, 4, 3, 4, 5, 5, 6, 7, 6, 7, 8, 8, 9, 10, 9, 10, 11, 11, 12, 13, 12, 13, 14, 14, 15, 16, 15, 16, 17, 17, 18, 19, 18, 19, 20, 20, 21, 22, 21, 22, 23, 23, 24, 25, 24, 25, 26, 26, 27, 28, 27, 28, 29, 29, 30, 31, 30, 31, 32, 32, 33, 34, 33, 34, 35, 35, 36, 37, 36, 37, 38

Offset

0,4

Links

Table of n, a(n) for n=0..75.

Index entries for linear recurrences with constant coefficients, signature (1,0,0,0,0,1,-1).

Formula

G.f.: (1+x^2+2x^3+2x^4+3x^5+2x^6+3x^7+2x^8+x^9+x^10)/(1-x^6)^2; a(n)=sum{k=0..n, -mu(k mod 6)}.

Mathematica

LinearRecurrence[{1, 0, 0, 0, 0, 1, -1}, {1, 0, 1, 2, 2, 3, 4}, 80] (* Harvey P. Dale, Oct 04 2021 *)

Crossrefs

Cf. A008611, A106249, A106250.

Sequence in context: A185977 A204006 A369879 * A134478 A051162 A122872

Adjacent sequences: A106248 A106249 A106250 * A106252 A106253 A106254

Keyword

easy,nonn

Author

Paul Barry, Apr 27 2005

Status

approved