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A052349
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a(n) = smallest nonprime such that every subset of a(1), ..., a(n) adds to a nonprime.
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9
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1, 8, 24, 25, 86, 1260, 1890, 14136, 197400, 10467660, 1231572090, 682616834970
(list; graph; refs; listen; history; internal format)
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OFFSET
| 1,2
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COMMENTS
| This set was defined by T. W. A. Baumann for The Prime Puzzles and Problems pages. He and C. Rivera obtained the first 10 members. Chris Nash proved that this sequence is infinite.
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LINKS
| Carlos Rivera, Puzzle 84
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EXAMPLE
| a(4) = 25 as 25+1, 25+8, 25+24, 25+1+8, 25+1+24, 25+8+24 and finally 25+1+8+24 all are composite numbers.
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CROSSREFS
| Cf. A068638.
Cf. A128687 (restricted to odd numbers), A128688 (restricted to even numbers).
Sequence in context: A005878 A128637 A109272 * A029607 A060476 A195086
Adjacent sequences: A052346 A052347 A052348 * A052350 A052351 A052352
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KEYWORD
| hard,nonn,nice
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AUTHOR
| Carlos B. Rivera F. (crivera(AT)primepuzzles.net), Mar 07 2000
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EXTENSIONS
| One more term from T. D. Noe (noe(AT)sspectra.com), Mar 20 2007
a(12) from Donovan Johnson (donovan.johnson(AT)yahoo.com), Jun 26 2010
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