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A302600 1, 2, prime numbers of prime index, and prime numbers of prime index times 2. 0
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 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

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.

LINKS

Table of n, a(n) for n=1..56.

EXAMPLE

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}}

MATHEMATICA

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

CROSSREFS

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

Sequence in context: A130689 A024560 A000039 * A053436 A057546 A138587

Adjacent sequences:  A302597 A302598 A302599 * A302601 A302602 A302603

KEYWORD

nonn

AUTHOR

Gus Wiseman, Apr 10 2018

STATUS

approved

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Last modified September 28 13:24 EDT 2020. Contains 337393 sequences. (Running on oeis4.)