a(n) is a generalized pentagonal number such that 2*a(n) is also a generalized pentagonal number.
A305539
a(n) is a generalized pentagonal number such that 2*a(n) is also a generalized pentagonal number.
Terms
- a(0) =0a(1) =1a(2) =35a(3) =1190a(4) =40426a(5) =1373295a(6) =46651605a(7) =1584781276a(8) =53835911780
External references
- oeis: A305539