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A155475
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Even composites n such that smallest digit of n < smallest digit of n-th prime.
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0
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4, 10, 12, 14, 16, 20, 22, 24, 30, 40, 50, 60, 70, 72, 90, 92, 100, 102, 104, 106, 108, 118, 120, 122, 124, 130, 132, 134, 136, 138, 144, 146, 148, 150, 154, 158, 160, 162, 166, 168, 190, 200, 202, 204, 206, 208, 210, 220, 230, 240, 250, 260, 270, 280, 290, 300
(list; graph; refs; listen; history; internal format)
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OFFSET
| 1,1
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EXAMPLE
| If n=4=even composite and 7=prime(4), then 4<7 and 4=a(1). If n=6=even composite and 13=prime(6), then 6>1. If n=8=even composite and 19=prime(8), then 8>1. If n=10=even composite and 29=prime(10), then 0<2 and 10=a(2). If n=12=even composite and 37=prime(12), then 1<3 and 12=a(3), etc.
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MATHEMATICA
| Select[2*Range[2, 160], Min[IntegerDigits[#]] < Min[IntegerDigits[Prime[ #]]]&] (* From Harvey P. Dale, Aug 18 2011 *)
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CROSSREFS
| Cf. A000027, A000040, A005843.
Sequence in context: A170943 A102998 A071179 * A023693 A181053 A077654
Adjacent sequences: A155472 A155473 A155474 * A155476 A155477 A155478
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KEYWORD
| nonn,base
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AUTHOR
| Juri-Stepan Gerasimov (2stepan(AT)rambler.ru), Jan 23 2009
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EXTENSIONS
| Corrected (150 inserted, 160 inserted, other 160 replaced by 260) by R. J. Mathar (mathar(AT)strw.leidenuniv.nl), May 10 2010
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