Odd decagonal pyramidal numbers.

Terms

a(0) =1a(1) =11a(2) =175a(3) =301a(4) =1005a(5) =1375a(6) =3003a(7) =3745a(8) =6681a(9) =7923a(10) =12551a(11) =14421a(12) =21125a(13) =23751a(14) =32915a(15) =36425a(16) =48433a(17) =52955a(18) =68191a(19) =73853a(20) =92701a(21) =99631a(22) =122475a(23) =130801a(24) =158025a(25) =167875a(26) =199863a(27) =211365a(28) =248501a(29) =261783