login
The OEIS Foundation is supported by donations from users of the OEIS and by a grant from the Simons Foundation.

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A190513 a(n) = n + [ns/r] + [nt/r] + [nu/r] + [nv/r] + [nw/r], where r=sin(x), s=cos(x), t=tan(x), u=csc(x), v=sec(x), w=cot(x), x=Pi/5. 8
9, 19, 31, 41, 52, 64, 74, 85, 97, 107, 118, 129, 140, 151, 162, 173, 184, 195, 205, 216, 227, 239, 249, 261, 271, 282, 294, 304, 313, 327, 337, 348, 359, 370, 381, 392, 402, 412, 425, 436, 447, 457, 469, 480, 490, 501, 513, 523, 534, 545, 557, 567, 578, 589, 599, 612, 621, 631, 644, 655, 665, 677, 687, 699 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

This is one of six sequences that partition the positive integers. In general, suppose that r, s, t, u, v, w are positive real numbers for which the sets {i/r : i>=1}, {j/s : j>=1}, {k/t : k>=1, {h/u : h>=1}, {p/v : p>=1}, {q/w : q>=1} are pairwise disjoint. Let a(n) be the rank of n/r when all the numbers in the six sets are jointly ranked. Define b(n), c(n), d(n), e(n), f(n) as the ranks of n/s, n/t, n/u, n/v, n/w respectively. It is easy to prove that

  a(n) = n + [ns/r] + [nt/r] + [nu/r] + [nv/r] + [nw/r],

  b(n) = [nr/s] + [nt/s] + [nu/s] + [nv/s] + [nw/s],

  c(n) = [nr/t] + [ns/t] + [nu/t] + [nv/t] + [nw/t],

  d(n) = n + [nr/u] + [ns/u] + [nt/u] + [nv/u] + [nw/u],

  e(n) = n + [nr/v] + [ns/v] + [nt/v] + [nu/v] + [nw/v],

  f(n) = n + [nr/w] + [ns/w] + [nt/w] + [nu/w] + [nv/w], where []=floor. Choosing r=sin(x), s=cos(x), t=tan(x), u=csc(x), v=sec(x), w=cot(x), x=Pi/5, gives a=A190513, b=A190514, c=A190515, d=A190516, e=A190517, f=A190518.

LINKS

Table of n, a(n) for n=1..64.

MATHEMATICA

x = Pi/5;

r=Sin[x]; s=Cos[x]; t=Tan[x]; u=1/r; v=1/s; w=1/t;

p[n_, h_, k_] := Floor[n*h/k]

a[n_]:=n+p[n, s, r]+p[n, t, r]+p[n, u, r]+p[n, v, r]+p[n, w, r]

b[n_]:=n+p[n, r, s]+p[n, t, s]+p[n, u, s]+p[n, v, s]+p[n, w, s]

c[n_]:=n+p[n, r, t]+p[n, s, t]+p[n, u, t]+p[n, v, t]+p[n, w, t]

d[n_]:=n+p[n, r, u]+p[n, s, u]+p[n, t, u]+p[n, v, u]+p[n, w, u]

e[n_]:=n+p[n, r, v]+p[n, s, v]+p[n, t, v]+p[n, u, v]+p[n, w, v]

f[n_]:=n+p[n, r, w]+p[n, s, w]+p[n, t, w]+p[n, u, w]+p[n, v, w]

Table[a[n], {n, 1, 120}]  (*A190513*)

Table[b[n], {n, 1, 120}]  (*A190514*)

Table[c[n], {n, 1, 120}]  (*A190515*)

Table[d[n], {n, 1, 120}]  (*A190516*)

Table[e[n], {n, 1, 120}]  (*A190517*)

Table[f[n], {n, 1, 120}]  (*A190518*)

CROSSREFS

Cf. A190514, A190515, A190516, A190517, A190518 (the other members of the partition).

Sequence in context: A330171 A189798 A056126 * A190576 A250663 A274590

Adjacent sequences:  A190510 A190511 A190512 * A190514 A190515 A190516

KEYWORD

nonn

AUTHOR

Clark Kimberling, May 11 2011

STATUS

approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified September 24 22:46 EDT 2021. Contains 347651 sequences. (Running on oeis4.)