The index of the first of two consecutive positive triangular numbers (A000217) the sum of which is equal to the sum of three consecutive positive triangular numbers.

A262489

The index of the first of two consecutive positive triangular numbers (A000217) the sum of which is equal to the sum of three consecutive positive triangular numbers.

Terms

    a(0) =7a(1) =18a(2) =78a(3) =187a(4) =781a(5) =1860a(6) =7740a(7) =18421a(8) =76627a(9) =182358a(10) =758538a(11) =1805167a(12) =7508761a(13) =17869320a(14) =74329080a(15) =176888041a(16) =735782047a(17) =1751011098a(18) =7283491398a(19) =17333222947a(20) =72099131941a(21) =171581218380a(22) =713707828020

External references