A325797 Numbers with fewer divisors than the sum of their prime indices.
5, 7, 9, 11, 13, 14, 15, 17, 19, 21, 22, 23, 25, 26, 27, 29, 31, 33, 34, 35, 37, 38, 39, 41, 43, 44, 45, 46, 47, 49, 50, 51, 52, 53, 55, 57, 58, 59, 61, 62, 63, 65, 67, 68, 69, 71, 73, 74, 75, 76, 77, 78, 79, 81, 82, 83, 85, 86, 87, 89, 91, 92, 93, 94, 95, 97
Offset: 1
Keywords
Examples
The sequence of terms together with their prime indices begins: 5: {3} 7: {4} 9: {2,2} 11: {5} 13: {6} 14: {1,4} 15: {2,3} 17: {7} 19: {8} 21: {2,4} 22: {1,5} 23: {9} 25: {3,3} 26: {1,6} 27: {2,2,2} 29: {10} 31: {11} 33: {2,5} 34: {1,7} 35: {3,4}
Crossrefs
Programs
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Mathematica
Select[Range[100],DivisorSigma[0,#]
PrimePi[p]*k]]&]
Comments