A187337 Sum{floor(kn/7), k=1,2,3,4,5,6}.

0, 0, 3, 6, 9, 12, 15, 21, 21, 24, 27, 30, 33, 36, 42, 42, 45, 48, 51, 54, 57, 63, 63, 66, 69, 72, 75, 78, 84, 84, 87, 90, 93, 96, 99, 105, 105, 108, 111, 114, 117, 120, 126, 126, 129, 132, 135, 138, 141, 147, 147, 150, 153, 156, 159, 162, 168, 168, 171, 174, 177, 180, 183, 189, 189, 192, 195, 198, 201, 204, 210, 210, 213, 216, 219, 222, 225, 231, 231, 234, 237, 240, 243, 246, 252, 252, 255, 258, 261, 264, 267, 273, 273, 276, 279, 282, 285, 288, 294, 294, 297, 300

Offset

0,3

Links

Table of n, a(n) for n=0..101.

Formula

a(n)=Sum{floor(kn/7), k=1,2,3,4,5,6}.

Empirical g.f.: 3*x^2*(2*x^5 +x^4 +x^3 +x^2 +x +1) / ((x-1)^2*(x^6 +x^5 +x^4 +x^3 +x^2 +x +1)). - Colin Barker, Mar 20 2013

Mathematica

Table[Sum[Floor[k*n/7], {k, 1, 6}], {n, 0, 120}

Crossrefs

Sequence in context: A220657 A194273 A123581 * A371000 A184999 A289761

Adjacent sequences: A187334 A187335 A187336 * A187338 A187339 A187340

Keyword

nonn

Author

Clark Kimberling, Mar 08 2011

Status

approved