a(n) is the smallest n-gonal pyramidal number with exactly n prime factors (counted with multiplicity).
A358865
a(n) is the smallest n-gonal pyramidal number with exactly n prime factors (counted with multiplicity).
Terms
- a(0) =20a(1) =140a(2) =405a(3) =2856a(4) =25296a(5) =111720a(6) =25984a(7) =5474000a(8) =237600a(9) =223826688a(10) =3852800a(11) =268565760a(12) =1834725376a(13) =175861400000a(14) =335674368a(17) =206015846400a(18) =3400704000
External references
- oeis: A358865