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A086887 a(n)=least semiprime with factors not previously used containing integers 2n and 2n+1 as substrings. 0
1111, 6, 205, 427, 1577, 11639, 1651, 22499, 2771, 34571, 253411, 5129, 60491, 59701, 8149, 9517, 307793, 122491, 13579, 53237, 168019, 18103, 202451, 21667, 169963, 377753, 27613, 301337, 88391, 34633, 368413, 750523, 418573, 44287 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,1

LINKS

Table of n, a(n) for n=0..33.

EXAMPLE

Sequence:....1111....6...205...427...1577....11639....1651..

Factors.:..101*11..2*3..41*5..61*7..83*19..103*113..127*13..

2n, 2n+1:.....0,1..2,3...4,5...6,7....8,9....10,11...12,13..

n ......:.......0....1.....2.....3......4........5.......6..

CROSSREFS

Sequence in context: A147589 A287283 A277927 * A278870 A278898 A278915

Adjacent sequences:  A086884 A086885 A086886 * A086888 A086889 A086890

KEYWORD

base,easy,nonn

AUTHOR

Jason Earls, Aug 22 2003

EXTENSIONS

More terms from Ray Chandler, Aug 31 2003

STATUS

approved

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Last modified April 16 18:53 EDT 2021. Contains 343050 sequences. (Running on oeis4.)