A277971 a(1) = 1; a(n) > a(n-1) is the smallest number whose name in English contains the first letter of the name of a(n-1).

1, 2, 3, 8, 9, 10, 12, 13, 14, 15, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 64, 65, 66, 67, 68, 69, 70, 71, 72, 73, 74, 75, 76, 77, 78, 79, 86, 87, 88, 89, 90, 91

Offset: 1

Author

Ivan N. Ianakiev, Nov 07 2016

Keywords

• easy
• nonn
• word

Crossrefs

Cf. A277972.

Programs

Mathematica

name[n_]:=IntegerName[n,"Words"];a[1]=1;
a[n_]:=a[n]=Module[{i=a[n-1]+1},While[
!StringContainsQ[name[i],StringTake[name[a[n-1]],1]],i++ ];i];
a/@Range[68] (* Ivan N. Ianakiev, Dec 20 2021 *)