A036843 Floor(X/Y), where X = concatenation of the triangular numbers and Y = concatenation of natural numbers.

1, 1, 1, 11, 110, 1102, 11024, 110242, 1102422, 1102422, 1102422, 1102422, 1102422, 11024223, 110242233, 1102422331, 11024223315, 110242233152, 1102422331526, 11024223315266, 110242233152667, 1102422331526679

Offset

1,4

Comments

a(n) -> 11024223315266792255432504568329867353511401594905438085....

Links

Table of n, a(n) for n=1..22.

Mathematica

f[n_] := (k = 1; x = y = "0"; While[k < n + 1, x = StringJoin[x, ToString[k(k+1)/2]]; y = StringJoin[y, ToString[k]]; k++ ]; Return[ Floor[ ToExpression[x] / ToExpression[y]]] ); Table[ f[n], {n, 1, 25} ]
Module[{nn=30, trs, nts}, trs=IntegerDigits/@Accumulate[Range[nn]]; nts= IntegerDigits/@ Range[nn]; Table[Floor[ FromDigits[Flatten[ Take[trs, n]]]/ FromDigits[ Flatten[ Take[nts, n]]]], {n, nn}]] (* Harvey P. Dale, Jul 15 2017 *)

Crossrefs

Cf. A007908.

Sequence in context: A109217 A266680 A320890 * A299301 A278786 A279826

Adjacent sequences: A036840 A036841 A036842 * A036844 A036845 A036846

Keyword

nonn,base,less

Author

Robert G. Wilson v, Jan 09 2002

Extensions

Edited by Charles R Greathouse IV, Apr 28 2010

Status

approved