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A217573
Number of integers between -(2*n+1)*Pi and (2*n+2)*Pi.
1
10, 22, 34, 47, 60, 72, 84, 98, 110, 122, 135, 148, 160, 172, 186, 198, 210, 223, 236, 248, 260, 274, 286, 298, 311, 324, 336, 348, 362, 374, 386, 399, 412, 424, 436, 450, 462, 474, 487, 500, 512, 524, 538, 550, 562, 575, 588, 600, 612, 626, 638, 650, 663
OFFSET
0,1
COMMENTS
a(n) is the number of lattice points inside spiral r=theta and on X-axis counted until the (n+1)-th loop of the spiral.
LINKS
FORMULA
a(n) = floor((2*n+1)*Pi) + floor((2*n+2)*Pi) + 1.
MAPLE
A := []:
for n from 0 to 80 do
n1 := floor((2*n+1)*Pi):
n2 := floor((2*n+2)*Pi):
A := [op(A), n1+n2+1]
end do:
A:=A;
MATHEMATICA
Table[Ceiling[Pi(2n+2)]+Floor[Pi(2n+1)], {n, 0, 60}] (* Harvey P. Dale, Aug 25 2014 *)
CROSSREFS
Cf. A001951.
Sequence in context: A339003 A017641 A232540 * A276626 A211482 A177791
KEYWORD
nonn
AUTHOR
César Eliud Lozada, Oct 08 2012
STATUS
approved