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

Offset: 1

Author

Henry Bottomley, Jul 06 2002

Keywords

• base
• nonn

Comments

A probability argument suggests that this sequence may be finite.

Examples

			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).
		

Crossrefs

Cf. A067121, A072723, A072725.

Programs

Mathematica

With[{eds=Range[2,1500,2]},Select[Table[FromDigits[Flatten[ IntegerDigits/@ Take[eds,n]]]/Total[Take[eds,n]],{n,502}],IntegerQ]] (* Harvey P. Dale, Nov 29 2011 *)