login
A183863
n-1+ceiling((2/5)(-1/2+n^2)); complement of A183862.
1
1, 3, 6, 10, 14, 20, 26, 33, 41, 49, 59, 69, 80, 92, 104, 118, 132, 147, 163, 179, 197, 215, 234, 254, 274, 296, 318, 341, 365, 389, 415, 441, 468, 496, 524, 554, 584, 615, 647, 679, 713, 747, 782, 818, 854, 892, 930, 969, 1009, 1049, 1091, 1133, 1176, 1220, 1264, 1310, 1356, 1403, 1451, 1499, 1549, 1599, 1650, 1702, 1754, 1808, 1862, 1917, 1973, 2029
OFFSET
1,2
FORMULA
a(n)=n-1+ceiling((2/5)(-1/2+n^2)).
MATHEMATICA
a=5/2; b=1/2;
Table[n+Floor[(a*n+b)^(1/2)], {n, 80}]
Table[n-1+Ceiling[(n*n-b)/a], {n, 70}]
CROSSREFS
Cf., A183862.
Sequence in context: A236758 A272058 A244360 * A372637 A140949 A025206
KEYWORD
nonn,easy
AUTHOR
Clark Kimberling, Jan 07 2011
STATUS
approved