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A214066
a(n) = floor( (3/2)*floor(5*n/2) ).
3
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
0,2
COMMENTS
Also, numbers that are congruent to {0,3,7,10} mod 15. - Bruno Berselli, Jul 19 2012
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
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}]
PROG
From Bruno Berselli, Jul 19 2012: (Start)
(Magma) [n: n in [0..190] | n mod 15 in [0, 3, 7, 10]];
(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)
CROSSREFS
Cf. A214068.
Sequence in context: A224880 A043722 A288175 * A120738 A190306 A189530
KEYWORD
nonn,easy
AUTHOR
Clark Kimberling, Jul 18 2012
STATUS
approved