A067119 a(n) = floor[X/Y] where X = concatenation of first n even numbers in increasing order and Y = n-th triangular number.

2, 8, 41, 246, 16454, 1175286, 88146471, 6855836706, 548466936480, 44874567530214, 3739547294184576, 316423232584848746, 27121991364415606839, 2350572584916019259453, 205675101180151685202190

Offset

1,1

Links

Harvey P. Dale, Table of n, a(n) for n = 1..352

Example

a(4) = floor[2468/(1+2+3+4)] = floor[246.8] = 246.

Maple

for i from 1 to 33 do n := 2*i:c := n:n := n-2:while(n>0) do g := floor(log(c+1)/log(10)):c := c+10^(g+1)*n:n := n-2:end do:a[i] := floor(2*c/i/(i+1)):end do:q := seq(a[j], j=1..33);

Mathematica

Module[{nn=20}, Table[Floor[FromDigits[Flatten[IntegerDigits/@Range[2, 2n, 2]]]/((n(n+1))/2)], {n, nn}]] (* Harvey P. Dale, Oct 03 2019 *)

Crossrefs

Cf. A067112-A067118.

Sequence in context: A217362 A294084 A177340 * A093935 A099240 A134055

Adjacent sequences: A067116 A067117 A067118 * A067120 A067121 A067122

Keyword

easy,nonn,base

Author

Amarnath Murthy, Jan 08 2002

Extensions

More terms from Sascha Kurz, Mar 23 2002

Edited by Charles R Greathouse IV, Apr 27 2010

Status

approved