A100814 Digits 9 to 0 are written in order with increasing number of digits for each member of the sequence. Leading zeros are counted, but are not written down.

9, 87, 654, 3210, 98765, 432109, 8765432, 10987654, 321098765, 4321098765, 43210987654, 321098765432, 1098765432109, 87654321098765, 432109876543210, 9876543210987654, 32109876543210987, 654321098765432109

Offset

1,1

Comments

This is similar to A062273 and A007923

References

C. Ashbacher, "Some problems concerning the Smarandache deconstructive sequence", Journal of Recreational Mathematics, vol. 29(2), 82-84 (1998)

Russell Euler and Jawad Sadek, "Some divisibility patterns in the Smarandache deconstructive sequence", Journal of Recreational Mathematics, vol. 31(1), 12-14 (2002-2003)

Links

Table of n, a(n) for n=1..18.

Example

The first number in the sequence is 9.
The second number in the sequence is 87.
The third number in the sequence is 654.

Mathematica

With[{c=PadRight[{}, 250, Range[9, 0, -1]]}, Table[FromDigits[Take[c, {(n(n+1))/2+1, ((n+1)(n+2))/2}]], {n, 0, 20}]] (* Harvey P. Dale, Jan 17 2017 *)

Crossrefs

Cf. A007923, A062273.

Sequence in context: A028339 A180751 A266828 * A055725 A219123 A144852

Adjacent sequences: A100811 A100812 A100813 * A100815 A100816 A100817

Keyword

nonn,easy,base

Author

Parthasarathy Nambi, Jan 05 2005

Extensions

More terms from Robert G. Wilson v and Lior Manor, Jan 14 2005

Status

approved