A266851 The last letter of the English name of a(n) equals the a(n)-th letter of the concatenation of all the terms spelled out in English.

4, 2, 10, 8, 9, 16, 18, 25, 33, 40, 50, 55, 60, 70, 78, 81, 83, 98, 99, 119, 125, 133, 139, 153, 155, 157, 168, 188, 201, 215, 217, 221, 241, 277, 293, 331, 337, 365, 367, 368, 378, 394, 395, 402, 410, 419, 423, 425, 434, 435, 437, 448, 451, 467, 473, 479, 484, 494, 495, 500, 506, 512, 523, 528, 531, 533, 539, 544, 545, 561

Offset

1,1

Links

Table of n, a(n) for n=1..70.

Example

a(2)=2, so that the last letter of two, o, is the 2nd letter of a(1)=4, four.

Prog

(PARI) A266851(n, show=1, a=4, u=0, s=[], E=k->select(t->t>"@", Vec(English(k))))={for(n=2, n, show&&print1(a", "); s=concat(s, E(a)); u+=1<<a; for(k=1, 9e9, !bittest(u, k)&&E(k)[-1..-1]==if(k<=#s, s[k..k], E(k)[k-#s..k-#s])&&(a=k)&&next(2))); a} \\ Uses English() from A052360. Optional args allow imposing special constraints or use of another language.

Crossrefs

Sequence in context: A213587 A066579 A117821 * A185732 A121794 A250108

Adjacent sequences: A266848 A266849 A266850 * A266852 A266853 A266854

Keyword

nonn,word

Author

Eric Angelini, Hans Havermann and M. F. Hasler, Jan 04 2016

Status

approved