

A282637


a(1) = 1. a(n) is the smallest unlisted natural number whose name in (American) English ends with the letter a(n1) starts with, and makes the sequence extendable.


1



1, 2, 8, 3, 28, 38, 88, 9, 10, 98, 11, 12, 108, 22, 128, 32, 138, 82, 21, 148, 92, 13, 158, 102, 122, 132, 142, 152, 162, 172, 182, 192, 202, 168, 222, 178, 232, 188, 242, 198, 252, 208, 228, 238, 248, 258, 268, 278, 288, 298, 308, 328, 338, 348, 358, 368, 378, 388, 398, 808, 23, 828, 25, 838, 29, 848
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OFFSET

1,2


COMMENTS

"a(n) ... makes the sequence extendable" means the name of a(n) does not start with any of the letters f and s.


LINKS

Table of n, a(n) for n=1..66.


EXAMPLE

38 is followed by 88 as 48, 58, 68 and 78 cannot make the sequence extendable.


MATHEMATICA

names = StringReplace[
IntegerName /@ Range[1000], {"\[Hyphen]" > "", " " > ""}];
lst = {1}; next[n_] := next[n] =
Module[{pos = Complement[Range[Length[names]], lst], i = 1},
While[
Or[
And[
First[Characters[names[[Last[lst]]]]] != Last[Characters[names[[pos[[i]]]]]],
pos[[i]] <= Length[names]
],
MemberQ[{"f", "s"}, First[Characters[names[[pos[[i]]]]]]] == True
],
i++
];
AppendTo[lst, pos[[i]]]
];
seq[n_] := Nest[next, 1, n]; seq[65]


CROSSREFS

Cf. A277971, A277972, A281067, A281068, A282636.
Sequence in context: A264244 A292930 A126951 * A256411 A218609 A268491
Adjacent sequences: A282634 A282635 A282636 * A282638 A282639 A282640


KEYWORD

easy,nonn,word


AUTHOR

Ivan N. Ianakiev, Feb 20 2017


STATUS

approved



