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A336548 Numbers k for which Product_{p^e|k} A051027(p^e) > A051027(k). Here each p^e is the maximal power of prime p that divides k, and A051027(k) = sigma(sigma(k)). 8
10, 15, 21, 22, 30, 33, 34, 35, 39, 40, 42, 46, 51, 52, 55, 57, 58, 60, 65, 66, 69, 70, 77, 78, 82, 84, 85, 87, 88, 90, 91, 93, 94, 95, 98, 102, 105, 106, 110, 111, 114, 115, 118, 119, 120, 123, 129, 130, 132, 133, 135, 136, 138, 140, 141, 142, 143, 145, 152, 154, 155, 156, 159, 160, 161, 164, 165, 166, 168, 170 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Numbers at which points A051027 is not multiplicative.

If x is present, then also multiples y*x are present for all y for which gcd(x,y) = 1.

LINKS

Antti Karttunen, Table of n, a(n) for n = 1..25000

EXAMPLE

10 = 2*5 is present as sigma(sigma(2))*sigma(sigma(5)) = 4*12 = 48 > sigma(sigma(10)) = 39.

CROSSREFS

Cf. A051027, A336546, A336547 (complement), A336549.

Cf. A336357, A336558, A336560, A336561 (subsequences).

Positions of nonzero terms in A336562.

Sequence in context: A045161 A105156 A108614 * A115708 A068992 A325901

Adjacent sequences:  A336545 A336546 A336547 * A336549 A336550 A336551

KEYWORD

nonn

AUTHOR

Antti Karttunen, Jul 25 2020

STATUS

approved

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Last modified September 17 12:00 EDT 2021. Contains 347477 sequences. (Running on oeis4.)