OFFSET
1,1
COMMENTS
LINKS
Michael De Vlieger, Table of n, a(n) for n = 1..10000
FORMULA
EXAMPLE
The terms together with their prime indices begin:
6: {1,2} 57: {2,8} 106: {1,16}
10: {1,3} 58: {1,10} 111: {2,12}
14: {1,4} 62: {1,11} 115: {3,9}
15: {2,3} 65: {3,6} 118: {1,17}
21: {2,4} 69: {2,9} 119: {4,7}
22: {1,5} 74: {1,12} 122: {1,18}
26: {1,6} 77: {4,5} 123: {2,13}
33: {2,5} 82: {1,13} 129: {2,14}
34: {1,7} 85: {3,7} 133: {4,8}
35: {3,4} 86: {1,14} 134: {1,19}
36: {1,1,2,2} 87: {2,10} 141: {2,15}
38: {1,8} 91: {4,6} 142: {1,20}
39: {2,6} 93: {2,11} 143: {5,6}
46: {1,9} 94: {1,15} 145: {3,10}
51: {2,7} 95: {3,8} 146: {1,21}
55: {3,5} 100: {1,1,3,3} 155: {3,11}
MATHEMATICA
Select[Range[100], SameQ@@Last/@If[#==1, {}, FactorInteger[#]]&&PrimeNu[#]==2&]
CROSSREFS
KEYWORD
nonn
AUTHOR
Gus Wiseman, Dec 01 2023
STATUS
approved