0,1

a(n) has values in the range from sqrt(10n-1) to 3n (or, slightly weaker but prettier, in the range from 3*sqrt(n) to 3n).

Table of n, a(n) for n=0..63.

a(1)=3 because 3^2+4^2=(5*1)^2; a(2)=6 because 6^2+8^2=(5+2)^2; a(5)=7 since 7^2+24^2=(5*5)^2.

Cf. A036842, A055527.

Sequence in context: A242088 A103695 A122809 * A329517 A297567 A285402

Adjacent sequences: A066659 A066660 A066661 * A066663 A066664 A066665

nonn

Henry Bottomley, Jan 14 2002

approved