A097963 ["comma"], is the first, fifteenth, twenty-sixth, fortieth, ... character in this sentence, including spaces and punctuations.

1, 15, 26, 40, 50, 60, 70, 82, 97, 113, 137, 165, 190, 213, 237, 265, 290, 313, 339, 367, 396, 424, 452, 479, 507, 529, 556, 582, 610, 629, 655, 680, 703, 724, 753, 780, 805, 826, 854, 882, 911, 934, 962, 989, 1016, 1040, 1063, 1089, 1116, 1152, 1191, 1230

Offset: 1

Author

Ray G. Opao, Sep 21 2004

Keywords

• nonn
• base
• nice
• easy
• word

Comments

Yes, the definition begins with a comma!

Examples

			Label the coordinates:
00000000011111111112222222222333333333344444444445...
12345678901234567890123456789012345678901234567890... Then (comma)
["Comma"], is the first, fifteenth, twenty-sixth, fortieth, fiftieth, fifty-ninth, seventy-second, eighty-eighth, one hundred third, one hundred twenty-second, ... character.
		

Links

• Jon E. Schoenfield, Table of n, a(n) for n = 1..1000

Crossrefs

Cf. A055508, A005224, A049525.

Programs

Python

from itertools import accumulate, repeat
from num2words import num2words
A097963_list = [1]+list(accumulate(repeat(15,100), lambda x, : x+2+len(num2words(x,to='ordinal').replace(' and ',' ').replace(', ',' ')))) # _Chai Wah Wu, Aug 30 2021

Formula

After a(2) = 15, the remaining terms are given by the recursion a(n+1) = a(n) + 2 + length(OrdinalName(a(n))); e.g., a(3) = a(2) + 2 + length(OrdinalName(a(2))) = 15 + 2 + length("fifteenth") = 15 + 2 + 9 = 26. - Jon E. Schoenfield, Aug 13 2007

Extensions

Corrected and extended by Jon E. Schoenfield, Aug 13 2007