Numbers k such that triangular(k) - x and y - triangular(k) are both triangular numbers (A000217), where x is the nearest square below triangular(k), y is the nearest square above triangular(k).

A234143

Numbers k such that triangular(k) - x and y - triangular(k) are both triangular numbers (A000217), where x is the nearest square below triangular(k), y is the nearest square above triangular(k).

Terms

    a(0) =1a(1) =4a(2) =5a(3) =19a(4) =22a(5) =25a(6) =40a(7) =64a(8) =85a(9) =89a(10) =110a(11) =124a(12) =127a(13) =148a(14) =263a(15) =552a(16) =688a(17) =700a(18) =705a(19) =790a(20) =1804a(21) =2101a(22) =4009a(23) =4108a(24) =8680a(25) =11830a(26) =15889a(27) =22125a(28) =23611a(29) =23710

External references