A095866 Largest n-digit number - largest n-digit triangular number.

3, 8, 9, 129, 318, 1008, 2843, 8988, 38439, 121089, 42708, 88208, 2034819, 1749819, 2235879, 104271309, 447194784, 1234742858, 2234186964, 3266133123, 22172578524, 114481278033, 204796672749, 841526085621, 355055477499

Offset: 1

Author

Ray Chandler, Jun 28 2004

Keywords

• base
• easy
• nonn

Links

• Harvey P. Dale, Table of n, a(n) for n = 1..1000

Crossrefs

Cf. A068092, A068093, A068094, A095863, A095864, A095865.

Programs

Mathematica

lndt[n_]:=Module[{c=Floor[(Sqrt[8*10^n+1]-1)/2]},(c(c+1))/2]; Join[{3}, Table[ 10^n-1-lndt[n],{n,2,30}]] (* Harvey P. Dale, May 16 2017 *)

Formula

a(n) = 10^n - 1 - A095864(n).