A325700 - OEIS

A325700

Numbers with as many distinct even as distinct odd prime indices.

1, 6, 12, 14, 15, 18, 24, 26, 28, 33, 35, 36, 38, 45, 48, 51, 52, 54, 56, 58, 65, 69, 72, 74, 75, 76, 77, 86, 93, 95, 96, 98, 99, 104, 106, 108, 112, 116, 119, 122, 123, 135, 141, 142, 143, 144, 145, 148, 152, 153, 158, 161, 162, 172, 175, 177, 178, 185, 192

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OFFSET

1,2

COMMENTS

These are the Heinz numbers of the integer partitions counted by A241638.

A prime index of n is a number m such that prime(m) divides n. The multiset of prime indices of n is row n of A112798.

LINKS

Table of n, a(n) for n=1..59.

EXAMPLE

The sequence of terms together with their prime indices begins:

1: {}

6: {1,2}

12: {1,1,2}

14: {1,4}

15: {2,3}

18: {1,2,2}

24: {1,1,1,2}

26: {1,6}

28: {1,1,4}

33: {2,5}

35: {3,4}

36: {1,1,2,2}

38: {1,8}

45: {2,2,3}

48: {1,1,1,1,2}

51: {2,7}

52: {1,1,6}

54: {1,2,2,2}

56: {1,1,1,4}

58: {1,10}

MATHEMATICA

Select[Range[100], 0==Total[(-1)^PrimePi/@First/@If[#==1, {}, FactorInteger[#]]]&]

CROSSREFS

A324967(n) = A324966(n).

Cf. A001221, A026010, A028260, A045931, A063886, A097613, A112798, A130780, A239241, A241638, A325698, A325699.

Sequence in context: A318981 A105115 A366532 * A360551 A306999 A246048

Adjacent sequences: A325697 A325698 A325699 * A325701 A325702 A325703

KEYWORD

nonn

AUTHOR

Gus Wiseman, May 17 2019

STATUS

approved