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

1,2

Comments

Yes, the definition begins with a comma!

Links

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

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

Example

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.

Prog

(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

Crossrefs

Cf. A055508, A005224, A049525.

Sequence in context: A263108 A274182 A139566 * A063936 A240914 A205881

Adjacent sequences: A097960 A097961 A097962 * A097964 A097965 A097966

Keyword

nonn,base,nice,easy,word

Author

Ray G. Opao, Sep 21 2004

Extensions

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

Status

approved