A053093 Smallest composite which when sum of prime factors is repeatedly subtracted reaches a prime after n iterations.
8, 16, 27, 58, 104, 150, 186, 256, 324, 378, 576, 636, 805, 1470, 1520, 1564, 1612, 3478, 3864, 8022, 9996, 10548, 11573, 11946, 12006, 13587, 13640, 15156, 20504, 21204, 21252, 24017, 24080, 25823, 27989, 30067, 30866, 31165, 31212, 47628
Offset: 1
Keywords
Examples
a(5)=104. Iteration 1: 104=2*2*2*13 and sum of factors is 19; 104-19=85. Iteration 2: 85=5*17; 85-22=63. Iterations 3,4,5 produce 63-13=50, 50-12=38 and 38-21=17, a prime.
Links
- Paolo P. Lava, Table of n, a(n) for n = 1..100