OFFSET
1,1
COMMENTS
EXAMPLE
The sequence of terms together with their prime indices begins:
5: {3} 270: {1,2,2,2,3}
10: {1,3} 300: {1,1,2,3,3}
15: {2,3} 375: {2,3,3,3}
25: {3,3} 405: {2,2,2,2,3}
30: {1,2,3} 450: {1,2,2,3,3}
45: {2,2,3} 500: {1,1,3,3,3}
50: {1,3,3} 625: {3,3,3,3}
75: {2,3,3} 675: {2,2,2,3,3}
90: {1,2,2,3} 750: {1,2,3,3,3}
100: {1,1,3,3} 810: {1,2,2,2,2,3}
125: {3,3,3} 900: {1,1,2,2,3,3}
135: {2,2,2,3} 1000: {1,1,1,3,3,3}
150: {1,2,3,3} 1125: {2,2,3,3,3}
225: {2,2,3,3} 1215: {2,2,2,2,2,3}
250: {1,3,3,3} 1250: {1,3,3,3,3}
MATHEMATICA
Select[Range[1000], PrimeOmega[#]<=Total[Cases[FactorInteger[#], {p_, k_}:>k*PrimePi[p]]]/2&&Max@@First/@FactorInteger[#]==5&]
CROSSREFS
KEYWORD
nonn
AUTHOR
Gus Wiseman, May 16 2021
STATUS
approved