Indices k such that 10 plus the k-th triangular number is a perfect square.

Terms

a(0) =3a(1) =5a(2) =26a(3) =36a(4) =155a(5) =213a(6) =906a(7) =1244a(8) =5283a(9) =7253a(10) =30794a(11) =42276a(12) =179483a(13) =246405a(14) =1046106a(15) =1436156a(16) =6097155a(17) =8370533a(18) =35536826a(19) =48787044a(20) =207123803a(21) =284351733a(22) =1207205994a(23) =1657323356a(24) =7036112163a(25) =9659588405a(26) =41009466986a(27) =56300207076a(28) =239020689755a(29) =328141654053