Search: id:A028992 Results 1-1 of 1 results found. %I A028992 %S A028992 24,46,154,204,396,474,750,856,1216,1350,1794,1956,2484,2674,3286, %T A028992 3504,4200,4446,5226,5500,6364,6666,7614,7944,8976,9334,10450,10836, %U A028992 12036,12450,13734,14176,15544,16014,17466,17964,19500,20026,21646 %N A028992 Even 9-gonal (or enneagonal) numbers. %H A028992 Eric Weisstein's World of Mathematics, Source %F A028992 (1/2)[28n^2 + 60n + 33 + (14n+15)(-1)^n]. %Y A028992 Cf. A001106. %Y A028992 Sequence in context: A000496 A063323 A154590 this_sequence A040552 A098427 A105651 %Y A028992 Adjacent sequences: A028989 A028990 A028991 this_sequence A028993 A028994 A028995 %K A028992 nonn %O A028992 1,1 %A A028992 Patrick De Geest (pdg(AT)worldofnumbers.com) Search completed in 0.001 seconds