OFFSET
1,1
LINKS
Harvey P. Dale, Table of n, a(n) for n = 1..1000
FORMULA
a(n)=n+Floor[1/2+(n/2)^(1/2)].
EXAMPLE
MATHEMATICA
Table[n+Floor[1/2+(n/2)^(1/2)], {n, 100}]
Module[{nn=110}, Complement[Range[nn], PolygonalNumber[6, Range[ Floor[ (1+Sqrt[ 1+8nn])/4]]]]] (* Requires Mathematica version 10 or later *) (* Harvey P. Dale, Sep 22 2020 *)
PROG
(Python)
from math import isqrt
def A183218(n): return n+(isqrt(n<<1)+1>>1) # Chai Wah Wu, Aug 26 2024
CROSSREFS
KEYWORD
nonn
AUTHOR
Clark Kimberling, Jan 01 2011
STATUS
approved