Positions of heptagonal numbers in the EKG sequence.

Terms

a(0) =1a(1) =12a(2) =14a(3) =32a(4) =53a(5) =76a(6) =104a(7) =145a(8) =179a(9) =226a(10) =269a(11) =325a(12) =368a(13) =450a(14) =507a(15) =585a(16) =674a(17) =749a(18) =827a(19) =917a(20) =1019a(21) =1127a(22) =1230a(23) =1343a(24) =1473a(25) =1595a(26) =1708a(27) =1832a(28) =1997a(29) =2111