A006092 Numbers beginning with letter 't' when spelled out in English. (Formerly M0901)

2, 3, 10, 12, 13, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 200, 201, 202, 203, 204, 205, 206, 207, 208, 209, 210, 211, 212, 213, 214, 215, 216, 217, 218, 219, 220

Offset

1,1

Comments

The next 179 terms are all the numbers from 221 to 399. Assuming that '1000' is spelled 'one thousand', the following terms are the numbers in the intervals [x*1000 , x*1000+999] where x runs over all elements a(1),..,a(225) occurring up to there. Then the numbers in the intervals [x*10^6, (x+1)*10^6-1] appear, where x again runs over all preceding terms. M. F. Hasler, Mar 23 2011

References

Archimedeans Problems Drive, Eureka, 48 (1988), pages 55, 56, 99.

N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).

Links

Table of n, a(n) for n=1..46.

Formula

Let g_k(x) = (x^(2k) - x^(4k) + x^(10k) - x^(11k) + x^(12k) - x^(14k) + x^(20k) - x^(40k) + x^(200k) - x^(400k))/(1-x). Then the g.f. of the characteristic function of this sequence is sum(j>=0, g_{1000^j}(x).

Crossrefs

Sequence in context: A295577 A325256 A302388 * A015859 A022427 A061868

Adjacent sequences: A006089 A006090 A006091 * A006093 A006094 A006095

Keyword

word,nonn

Author

N. J. A. Sloane.

Status

approved