A372591 Numbers whose binary weight (A000120) plus bigomega (A001222) is even.
2, 6, 7, 8, 9, 10, 11, 13, 15, 19, 24, 28, 31, 32, 33, 34, 36, 37, 39, 40, 41, 42, 44, 46, 47, 50, 51, 52, 54, 57, 58, 59, 60, 61, 65, 67, 70, 73, 76, 77, 79, 85, 86, 90, 95, 96, 97, 98, 103, 106, 107, 109, 110, 111, 112, 117, 119, 123, 124, 126, 127, 128, 129
Offset: 1
Keywords
Examples
The terms (center), their binary indices (left), and their weakly decreasing prime indices (right) begin: {2} 2 (1) {2,3} 6 (2,1) {1,2,3} 7 (4) {4} 8 (1,1,1) {1,4} 9 (2,2) {2,4} 10 (3,1) {1,2,4} 11 (5) {1,3,4} 13 (6) {1,2,3,4} 15 (3,2) {1,2,5} 19 (8) {4,5} 24 (2,1,1,1) {3,4,5} 28 (4,1,1) {1,2,3,4,5} 31 (11) {6} 32 (1,1,1,1,1) {1,6} 33 (5,2) {2,6} 34 (7,1) {3,6} 36 (2,2,1,1) {1,3,6} 37 (12) {1,2,3,6} 39 (6,2) {4,6} 40 (3,1,1,1) {1,4,6} 41 (13) {2,4,6} 42 (4,2,1)
Crossrefs
Programs
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Mathematica
Select[Range[100],EvenQ[DigitCount[#,2,1]+PrimeOmega[#]]&]
Comments