Some curious polygonals

The 44^{th} enneagonal (9-sided polygonal) number is 6666 !

(Sloane's A028992)

The 26^{th} decagonal (10-sided polygonal) number is 2626 !

(Sloane's A001107)

The 74^{th} heptagonal (7-sided polygonal : n[5n-3]) number is 13579

(Sloane's A014637),
a number with its odd digits in ascending order !

Variations on the theme :