A359830 - OEIS

A359830

Numbers k such that A048675(k) is not a multiple of 3.

2, 3, 4, 5, 7, 9, 10, 11, 12, 13, 16, 17, 18, 19, 21, 22, 23, 24, 25, 28, 29, 30, 31, 32, 34, 37, 39, 40, 41, 42, 43, 45, 46, 47, 49, 52, 53, 54, 55, 56, 57, 59, 60, 61, 62, 66, 67, 70, 71, 72, 73, 75, 76, 78, 79, 80, 81, 82, 83, 85, 87, 88, 89, 91, 94, 96, 97, 98, 99, 100, 101, 102, 103, 104, 105, 107, 108

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OFFSET

1,1

COMMENTS

Sequence is closed with respect to prime shifting: for any k present in the sequence, also A003961(k) and A348717(k) are present.

LINKS

Table of n, a(n) for n=1..77.

Index entries for sequences computed from indices in prime factorization

PROG

(PARI)

A048675(n) = { my(f = factor(n)); sum(k=1, #f~, f[k, 2]*2^primepi(f[k, 1]))/2; };

isA359830(n) = !!(A048675(n)%3);