Smallest k such that circle centered at the origin and with radius sqrt(k) passes through exactly 6*n integer points in the hexagonal lattice (see A004016).
A343771
Smallest k such that circle centered at the origin and with radius sqrt(k) passes through exactly 6*n integer points in the hexagonal lattice (see A004016).
Terms
- a(0) =1a(1) =7a(2) =49a(3) =91a(4) =2401a(5) =637a(6) =117649a(7) =1729a(8) =8281a(9) =31213a(10) =282475249a(11) =12103a(12) =13841287201a(13) =1529437a(14) =405769a(15) =53599a(17) =157339a(19) =593047a(20) =19882681a(21) =3672178237a(23) =375193a(24) =68574961a(25) =179936733613a(26) =2989441a(27) =29059303a(29) =7709611
External references
- oeis: A343771