A164302 - OEIS

A164302

a(n) = 2* (the n-th positive (odd) integer that is a palindrome when written in base 2).

2, 6, 10, 14, 18, 30, 34, 42, 54, 62, 66, 90, 102, 126, 130, 146, 170, 186, 198, 214, 238, 254, 258, 306, 330, 378, 390, 438, 462, 510, 514, 546, 594, 626, 650, 682, 730, 762, 774, 806, 854, 886, 910, 942, 990, 1022, 1026, 1122, 1170, 1266, 1290, 1386, 1434

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OFFSET

1,1

COMMENTS

When written in binary, a(n) is the smallest positive integer that is not a palindrome, and that contains the n-th positive binary palindrome as a substring.

a(n) = 2 * A006995(n).

LINKS

Jasper Mulder, Table of n, a(n) for n=1..50000

EXAMPLE

The fifth positive integer that is a palindrome in base 2 is 9, which is 1001 in binary. a(5) therefore equals 18, which is 10010 in binary. 18 is the smallest integer, which when written in binary, it is not a palindrome and it contains 1001 as a substring.

CROSSREFS

Sequence in context: A281702 A281703 A180216 * A290727 A190883 A284678

Adjacent sequences: A164299 A164300 A164301 * A164303 A164304 A164305

KEYWORD

base,nonn

AUTHOR

Leroy Quet, Aug 12 2009

EXTENSIONS

More terms from Jasper Mulder (jasper.mulder(AT)planet.nl), Oct 12 2009

More terms from Sean A. Irvine, Nov 19 2009

Minor edits by Ray Chandler, Mar 16 2010

STATUS

approved