Multi-base happiness solutions

Multi-base happiness was solved using JavaScript by 4 contestants. Solution sizes: average 2363 bytes (shortest: 796; longest: 4959).

739.

L.S. (S) (2049 B)
1234.

alsanan (S) (796 B)
1371.

cel (S) (1650 B)
1920.

Seventoes (S) (4959 B)