id:A004075 - OEIS Search Results

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Number of Skolem sequences of order n.

+0
3

1, 0, 0, 6, 10, 0, 0, 504, 2656, 0, 0, 455936, 3040560, 0, 0, 1400156768, 12248982496, 0, 0, 11435578798976, 123564928167168, 0, 0 (list; graph; listen)

	OFFSET	`1,4`
	COMMENT	`For n>1, a(n)=A059106(n)*2 because A059106 ignores reflected solutions. - Martin Fuller (martin_n_fuller(AT)btinternet.com), Mar 08 2007`
	REFERENCES	`CRC Handbook of Combinatorial Designs, 1996, p. 460.`
	LINKS	`G. Nordh, Perfect Skolem sequences` `J. E. Miller, Langford's Problem`
	CROSSREFS	`Cf. A059106.` `Sequence in context: A061110 A110460 A159190 this_sequence A052193 A144763 A083478` `Adjacent sequences: A004072 A004073 A004074 this_sequence A004076 A004077 A004078`
	KEYWORD	`nonn`
	AUTHOR	`N. J. A. Sloane (njas(AT)research.att.com).`
	EXTENSIONS	`More terms (via A059106) from Martin Fuller (martin_n_fuller(AT)btinternet.com), Mar 08 2007`

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Last modified December 17 23:40 EST 2009. Contains 171025 sequences.

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