The On-Line Encyclopedia of Integer Sequences (OEIS)

Revision History for A353357 (Bold, blue-underlined text is an addition; faded, red-underlined text is a ~~deletion~~.)
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A353357

Numbers k for which A353328(k) < A353329(k). Positions of -1's in A353354.
(history; published version)

#13 by Michael De Vlieger at Mon Apr 25 16:59:40 EDT 2022

STATUS

proposed

approved

#12 by Peter Munn at Mon Apr 25 12:15:11 EDT 2022

STATUS

editing

proposed

#11 by Antti Karttunen at Sat Apr 23 11:32:24 EDT 2022

FORMULA

a(n : n >= 1} = {m : tau(m) * A048675(m) == 1 (mod 3)}, where tau is the number of divisors function, A000005.

Discussion

Mon Apr 25

12:15

Peter Munn: Edit to recent new sequence by the authors.

#10 by Antti Karttunen at Sat Apr 23 11:32:03 EDT 2022

CROSSREFS

Cf. A000005, A003961, A048675, A332823, A353328, A353329, A353354, A353355, A353356.

#9 by Antti Karttunen at Sat Apr 23 11:31:38 EDT 2022

CROSSREFS

Cf. A003961, A048675, A332823, A353328, A353329, A353354, A353355, A353356.

#8 by Antti Karttunen at Sat Apr 23 11:31:15 EDT 2022

PROG

(PARI)

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

isA353357(n) = (1==((numdiv(n)*A048675(n))%3));

#7 by Peter Munn at Sat Apr 23 10:08:36 EDT 2022

FORMULA

a(n : n >= 1} = {m : tau(m) * A048675(m) == 1 (mod 3)}, where tau is the number of divisors function.

STATUS

approved

editing

#6 by Michael De Vlieger at Tue Apr 19 17:35:24 EDT 2022

STATUS

proposed

approved

#5 by Antti Karttunen at Tue Apr 19 12:16:42 EDT 2022

STATUS

editing

proposed

#4 by Peter Munn at Tue Apr 19 11:31:51 EDT 2022

NAME

Numbers k for which A353328(k) < A353329(k). Positions of negative terms -1's in A353354.