A067120 a(n) = floor(X/Y) where X = concatenation of first n odd numbers in increasing order and Y = n-th triangular number.

1, 4, 22, 135, 905, 64662, 4849682, 377197536, 30175802922, 2468929330031, 205744110835938, 17409117070733232, 1492210034634277058, 129324869668304011738, 11315926095976601027106, 998464067292053031803477, 88752361537071380604753549, 7941000769106386685688475516

Offset

1,2

Links

Harvey P. Dale, Table of n, a(n) for n = 1..353

Example

a(4) floor[1357/(1+2+3+4)] = floor[135.7] = 135.

Maple

for i from 1 to 33 do n := 2*i-1:c := n:n := n-2:while(n>0) do g := floor(log(c)/log(10)):c := c+10^(g+1)*n:n := n-2:end do:a[i] := floor(2*c/i/(i+1)):end do:q2 := seq(a[j], j=1..33);

Mathematica

With[{nn=20}, Table[Floor[FromDigits[Flatten[IntegerDigits/@Range[1, 2n-1, 2]]]/((n(n+1))/2)], {n, nn}]] (* Harvey P. Dale, Feb 22 2020 *)

Crossrefs

Cf. A067112-A067119.

Sequence in context: A197657 A183280 A183281 * A143648 A069835 A007196

Adjacent sequences: A067117 A067118 A067119 * A067121 A067122 A067123

Keyword

easy,nonn,base,less

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