A214066 a(n) = floor( (3/2)*floor(5*n/2) ).

0, 3, 7, 10, 15, 18, 22, 25, 30, 33, 37, 40, 45, 48, 52, 55, 60, 63, 67, 70, 75, 78, 82, 85, 90, 93, 97, 100, 105, 108, 112, 115, 120, 123, 127, 130, 135, 138, 142, 145, 150, 153, 157, 160, 165, 168, 172, 175, 180, 183, 187, 190

Offset: 0

Author

Clark Kimberling, Jul 18 2012

Keywords

• nonn
• easy

Comments

Also, numbers that are congruent to {0,3,7,10} mod 15. - Bruno Berselli, Jul 19 2012

Links

• Clark Kimberling, Table of n, a(n) for n = 0..1000
• Index entries for linear recurrences with constant coefficients, signature (1,0,0,1,-1).

Crossrefs

Cf. A214068.

Programs

Magma

[n: n in [0..190] | n mod 15 in [0,3,7,10]];

Maple

A214066:=n->floor((3/2)*floor(5*n/2)): seq(A214066(n), n=0..100); # Wesley Ivan Hurt, Jun 04 2016

Mathematica

f[n_]:=Floor[(3/2)Floor[5n/2]]; t=Table[f[n], {n,0,70}]

Maxima

makelist((30*n+2*%i^((n-1)*n)+3*(-1)^n-5)/8, n, 0, 51);

PARI

concat(0, Vec((3+4*x+3*x^2+5*x^3)/((1+x)*(1-x)^2*(1+x^2))+O(x^51))) (End)

Formula

From Bruno Berselli, Jul 19 2012: (Start)

G.f.: x*(3+4*x+3*x^2+5*x^3)/((1+x)*(1-x)^2*(1+x^2)).

a(n) = (30*n+2*i^((n-1)*n)+3*(-1)^n-5)/8, where i=sqrt(-1). (End)

a(n) = a(n-1) + a(n-4) - a(n-5) for n>5. - Wesley Ivan Hurt, Jun 04 2016