login

Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 61st year, we have over 378,000 sequences, and we’ve reached 11,000 citations (which often say “discovered thanks to the OEIS”).

A187395
a(n) = floor(r*n), where r = 4 + sqrt(10); complement of A187396.
3
7, 14, 21, 28, 35, 42, 50, 57, 64, 71, 78, 85, 93, 100, 107, 114, 121, 128, 136, 143, 150, 157, 164, 171, 179, 186, 193, 200, 207, 214, 222, 229, 236, 243, 250, 257, 265, 272, 279, 286, 293, 300, 307, 315, 322, 329, 336, 343, 350, 358, 365, 372, 379, 386, 393, 401, 408, 415, 422, 429, 436, 444, 451, 458, 465, 472, 479, 487, 494, 501
OFFSET
1,1
COMMENTS
A187395 and A187396 are the Beatty sequences based on r = 4 + sqrt(10) and s = -2 + sqrt(10); 1/r + 1/s = 1.
FORMULA
a(n) = floor(r*n), where r = 4 + sqrt(10).
MATHEMATICA
r=4+10^(1/2); s=-2+10^(1/2);
Table[Floor[r*n], {n, 1, 80}] (* A187395 *)
Table[Floor[s*n], {n, 1, 80}] (* A187396 *)
PROG
(Python)
from sympy import integer_nthroot
def A187395(n): return 4*n+integer_nthroot(10*n**2, 2)[0] # Chai Wah Wu, Mar 16 2021
CROSSREFS
Cf. A187396.
Sequence in context: A206717 A043393 A028437 * A033019 A031483 A020334
KEYWORD
nonn
AUTHOR
Clark Kimberling, Mar 09 2011
EXTENSIONS
Edited by Clark Kimberling, Mar 17 2021
STATUS
approved