A105395 A simple "Fractal Jump Sequence" (FJS).

1, 1, 1, 7, 1, 1, 7, 1, 1, 7, 1, 1, 7, 1, 1, 7, 1, 1, 7, 1, 1, 7, 1, 1, 7, 1, 1, 7, 1, 1, 7, 1, 1, 7, 1, 1, 7, 1, 1, 7, 1, 1, 7, 1, 1, 7, 1, 1, 7, 1, 1, 7, 1, 1, 7, 1, 1, 7, 1, 1, 7, 1, 1, 7, 1, 1, 7, 1, 1, 7, 1, 1, 7, 1, 1, 7, 1, 1, 7, 1, 1, 7, 1, 1, 7, 1, 1, 7, 1, 1, 7, 1, 1, 7, 1, 1, 7, 1, 1, 7, 1, 1, 7, 1, 1

Offset

1,4

Comments

See A105397 for definition of Fractal Jump Sequence.

a(n+2) = the digital root of the n-th centered hexagonal number (A003215). - Colin Barker, Jan 30 2015

Links

Colin Barker, Table of n, a(n) for n = 1..1000

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

Formula

a(n) = a(n-3) for n>4. - Colin Barker, Jan 30 2015

G.f.: -x*(2*x+1)*(3*x^2-x+1) / ((x-1)*(x^2+x+1)). - Colin Barker, Jan 30 2015

Prog

(PARI) Vec(-x*(2*x+1)*(3*x^2-x+1)/((x-1)*(x^2+x+1))  + O(x^100)) \\ Colin Barker, Jan 30 2015

Crossrefs

Cf. A003215, A105397, A003215.

Sequence in context: A086384 A102421 A019620 * A120437 A336459 A367764

Adjacent sequences: A105392 A105393 A105394 * A105396 A105397 A105398

Keyword

base,easy,nonn

Author

Eric Angelini, May 01 2005

Status

approved