

A242313


Numbers belonging to a geometric sequence whose ratio is 2 and whose first term ends in 1.


0



1, 2, 4, 8, 11, 16, 21, 22, 31, 32, 41, 42, 44, 51, 61, 62, 64, 71, 81, 82, 84, 88, 91, 101, 102, 111, 121, 122, 124, 128, 131, 141, 142, 151, 161, 162, 164, 168, 171, 176, 181, 182, 191, 201, 202, 204, 211, 221, 222, 231, 241, 242, 244, 248, 251, 256, 261
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OFFSET

1,2


COMMENTS

Numbers such that A099551(n) = 1.
Numbers of the form 2^m * (10n + 1).  Charles R Greathouse IV, May 14 2014


LINKS

Table of n, a(n) for n=1..57.


FORMULA

a(n) = 5n + O(log n).  Charles R Greathouse IV, May 14 2014


EXAMPLE

176 is in sequence because it belongs to 11,22,44,88,176, with first term 11.
96, which belongs to 3,6,12,24,48,96 with first term 3, does not qualify.


PROG

(PARI) isok(n) = ((n/2^valuation(n, 2)) % 10) == 1; \\ Michel Marcus, May 14 2014


CROSSREFS

Cf. A099551.
Sequence in context: A320448 A115797 A336627 * A003596 A018600 A018408
Adjacent sequences: A242310 A242311 A242312 * A242314 A242315 A242316


KEYWORD

nonn,base,easy


AUTHOR

J. Lowell, May 10 2014


EXTENSIONS

More terms from Michel Marcus, May 14 2014


STATUS

approved



