A139097 Form a sequence of words as follows: look to the left, towards the beginning of the sequence and write down the number of letters you see; repeat; then replace the words with the corresponding numbers.

0, 4, 8, 13, 21, 30, 36, 45, 54, 63, 73, 85, 95, 105, 119, 137, 158, 178, 200, 211, 227, 248, 268, 288, 309, 325, 347, 369, 390, 408, 424, 445, 465, 485, 506, 520, 537, 559, 579, 601, 614, 632, 651, 669, 688, 709, 725, 747, 769, 790, 808, 825, 847, 869, 890, 908, 924, 945, 965, 985, 1006, 1020, 1037, 1059

Offset: 0

Author

Jonathan Vos Post, May 12 2007

Keywords

• nonn
• word
• easy

Comments

The sequence of words is: zero, four, eight, thirteen, twenty-one, thirty, ... (in American English).

Hyphens and spaces are not counted.

This is an English version of the sequence in A139121.

a(0) = 0, a(n+1) = a(n) + A005589(a(n)). - Jonathan Vos Post, Jun 15 2008

Examples

			The second word is "four" (and so a(2)=4), because at the end of the first word we can see four letters to the left.
		

References

• E. Angelini, "Jeux de suites", in Dossier Pour La Science, pp. 32-35, Volume 59 (Jeux math'), April/June 2008, Paris.

Links

• M. F. Hasler, Table of n, a(n) for n = 0..423

Crossrefs

Cf. A005589. See A060403 and A139121 for other versions.

Extensions

Edited by N. J. A. Sloane, Jun 08 2008

More terms from M. F. Hasler and R. J. Mathar, Jun 15 2008