a(n) is the smallest number which can be represented as the sum of two distinct nonzero hexagonal numbers in exactly n ways, or -1 if no such number exists.

A374141

a(n) is the smallest number which can be represented as the sum of two distinct nonzero hexagonal numbers in exactly n ways, or -1 if no such number exists.

Terms

    a(0) =7a(1) =384a(2) =4995a(3) =51106a(4) =204805a(5) =483031a(6) =2443431a(7) =4674256a(8) =10476781a(9) =17272531a(10) =25600656a(11) =60765331a(12) =90406956a(13) =206602126a(14) =332808531a(15) =481676406a(16) =303826656a(17) =435211156a(18) =789949306a(19) =1406495106a(20) =2260173906a(21) =2704798281a(22) =3220562556a(23) =4435869181a(24) =5165053156a(25) =5309576106a(26) =9818788281

External references