A072723 Integers which are exactly the concatenation of the first m odd numbers (A019519) divided by their sum (A000290 = m^2).

1, 15, 16764334957, 3079163563531047898532266016633501

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) = 1/1 = 1; a(2) = 135/(1+3+5) = 15; a(3) = 1357911131517/(1+3+5+7+9+11+13+15+17) = 16764334957; a(4) = 1357911131517192123252729313335373941/(1+3+5+7+9+11+13+15+17+19+21+23+25+27+29+31+33+35+37+39+41) = 3079163563531047898532266016633501.
		

Crossrefs

Cf. A067122, A072724, A072725.

Programs

Mathematica

Select[Table[FromDigits[Flatten[IntegerDigits/@Range[1,2n+1,2]]]/Total[Range[1,2n+1,2]],{n,0,30}],IntegerQ] (* Harvey P. Dale, Mar 24 2023 *)