Odd heptagonal pyramidal numbers.

Terms

a(0) =1a(1) =115a(2) =645a(3) =1911a(4) =4233a(5) =7931a(6) =13325a(7) =20735a(8) =30481a(9) =42883a(10) =58261a(11) =76935a(12) =99225a(13) =125451a(14) =155933a(15) =190991a(16) =230945a(17) =276115a(18) =326821a(19) =383383a(20) =446121a(21) =515355a(22) =591405a(23) =674591a(24) =765233a(25) =863651a(26) =970165a(27) =1085095a(28) =1208761a(29) =1341483