A072724 - OEIS

This site is supported by donations to The OEIS Foundation.

A072724

Integers which are exactly the concatenation of the first m even numbers (A019520) divided by their sum (A002378 = m^2+m).

1, 4, 8227, 3427918353 (list; graph; refs; listen; history; internal format)

	OFFSET	`1,2`
	COMMENTS	`A probability argument suggests that this sequence may be finite.`
	EXAMPLE	`a(1) = 2/2 =1; a(2) = 24/(2+4) = 4; a(3) = 246810/(2+4+6+8+10) = 8227; a(4) = 246810121416/(2+4+6+8+10+12+14+16).`
	MATHEMATICA	`With[{eds=Range[2, 1500, 2]}, Select[Table[FromDigits[Flatten[ IntegerDigits/@ Take[eds, n]]]/Total[Take[eds, n]], {n, 502}], IntegerQ]] (* From Harvey P. Dale, Nov 29 2011 *)`
	CROSSREFS	`Cf. A067121, A072723, A072725.` `Sequence in context: A053951 A058460 A115050 * A116271 A201392 A058417` `Adjacent sequences: A072721 A072722 A072723 * A072725 A072726 A072727`
	KEYWORD	`base,nonn`
	AUTHOR	`Henry Bottomley (se16(AT)btinternet.com), Jul 06 2002`

Content is available under The OEIS End-User License Agreement .

Last modified February 17 22:48 EST 2012. Contains 206085 sequences.