Triangular numbers whose internal digits form a triangular number. Or triangular number such that deleting the MSD and LSD leaves a triangular number.
A077366
Triangular numbers whose internal digits form a triangular number. Or triangular number such that deleting the MSD and LSD leaves a triangular number.
Terms
- a(0) =0a(1) =1a(2) =3a(3) =6a(4) =10a(5) =15a(6) =21a(7) =28a(8) =36a(9) =45a(10) =55a(11) =66a(12) =78a(13) =91a(14) =105a(15) =136a(16) =210a(17) =231a(18) =300a(19) =406a(20) =435a(21) =465a(22) =561a(23) =630a(24) =666a(25) =703a(26) =861a(27) =903a(28) =1035a(29) =2016
External references
- oeis: A077366