A302600 1, 2, prime numbers of prime index, and prime numbers of prime index times 2.

1, 2, 3, 5, 6, 10, 11, 17, 22, 31, 34, 41, 59, 62, 67, 82, 83, 109, 118, 127, 134, 157, 166, 179, 191, 211, 218, 241, 254, 277, 283, 314, 331, 353, 358, 367, 382, 401, 422, 431, 461, 482, 509, 547, 554, 563, 566, 587, 599, 617, 662, 706, 709, 734, 739, 773

Offset: 1

Author

Gus Wiseman, Apr 10 2018

Keywords

• nonn

Comments

A prime index of n is a number m such that prime(m) divides n.

Also squarefree numbers whose prime indices other than 1 are equal prime numbers.

Examples

			Entry A302242 describes a correspondence between positive integers and multiset multisystems. In this case it gives the following sequence of set systems.
01: {}
02: {{}}
03: {{1}}
05: {{2}}
06: {{},{1}}
10: {{},{2}}
11: {{3}}
17: {{4}}
22: {{},{3}}
31: {{5}}
34: {{},{4}}
41: {{6}}
59: {{7}}
62: {{},{5}}
67: {{8}}
82: {{},{6}}
83: {{9}}
		

Crossrefs

Cf. A000961, A001222, A003963, A005117, A007716, A056239, A275024, A047966, A281113, A296134, A301766, A302242, A302243.

Programs

Mathematica

Select[Range[1000],SquareFreeQ[#]&&SameQ@@DeleteCases[primeMS[#],1]&&And@@PrimeQ/@DeleteCases[primeMS[#],1]&]