1,2

94109401=7921*(3*7921)/2 is the 7921st pentagonal number and 94109401=89^2*109^2.

Cf. A001694, A000326.

Sequence in context: A145209 A035911 A069333 this_sequence A036353 A031687 A031597

Adjacent sequences: A113934 A113935 A113936 this_sequence A113938 A113939 A113940

nonn

Giovanni Resta (g.resta(AT)iit.cnr.it), Jan 31 2006