The On-Line Encyclopedia of Integer Sequences (OEIS)

Revision History for A337378

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A337378

Numbers k for which A003961(k) > 2*sigma(k).
(history; published version)

#11 by Susanna Cuyler at Thu Aug 27 17:08:09 EDT 2020

STATUS

proposed

approved

#10 by Antti Karttunen at Thu Aug 27 13:46:11 EDT 2020

STATUS

editing

proposed

#9 by Antti Karttunen at Thu Aug 27 13:36:21 EDT 2020

COMMENTS

Note that A003961(n) >= sigma(n), for all n. See A286385.

LINKS

Antti Karttunen, <a href="/A337378/b337378.txt">Table of n, a(n) for n = 1..20000</a>

CROSSREFS

Cf. A000203, A003961, A286385.

Cf. also A286385.

#8 by Antti Karttunen at Thu Aug 27 13:28:44 EDT 2020

CROSSREFS

Subsequence of A246282 and of A337381.

Cf. also A286385, A337381.

#7 by Antti Karttunen at Thu Aug 27 13:18:55 EDT 2020

CROSSREFS

Subsequence of A246282.

Cf. also A246282, A286385, A337381.

#6 by Antti Karttunen at Thu Aug 27 13:09:13 EDT 2020

COMMENTS

Note that A003961(n) >= sigma(n), for all n. See A286385.

CROSSREFS

Cf. also A246282, A286385, A337381.

#5 by Antti Karttunen at Thu Aug 27 13:06:42 EDT 2020

LINKS

<a href="/index/Pri#prime_indices">Index entries for sequences computed from indices in prime factorization</a>

<a href="/index/Si#SIGMAN">Index entries for sequences related to sigma(n)</a>

#4 by Antti Karttunen at Thu Aug 27 13:02:48 EDT 2020

CROSSREFS

Cf. also A246282, A337381.

#3 by Antti Karttunen at Thu Aug 27 12:34:36 EDT 2020

CROSSREFS

Cf. A337379 (complement), A337380 (characteristic function).

#2 by Antti Karttunen at Thu Aug 27 12:28:30 EDT 2020

NAME

allocated Numbers k for Antti Karttunenwhich A003961(k) > 2*sigma(k).

DATA

16, 24, 27, 32, 36, 40, 45, 48, 49, 54, 56, 63, 64, 72, 80, 81, 84, 90, 96, 98, 99, 100, 104, 105, 108, 112, 117, 120, 125, 126, 128, 135, 140, 144, 147, 152, 153, 160, 162, 168, 171, 175, 176, 180, 184, 189, 192, 196, 198, 200, 207, 208, 210, 216, 224, 225, 234, 240, 243, 245, 248, 250, 252, 256, 264, 270, 272, 273

OFFSET

1,1

PROG

(PARI)

A003961(n) = { my(f = factor(n)); for (i=1, #f~, f[i, 1] = nextprime(f[i, 1]+1)); factorback(f); };

isA337378(n) = (A003961(n)>2*sigma(n));

CROSSREFS

Cf. A000203, A003961.

Cf. A337379 (complement).

KEYWORD

allocated

nonn

AUTHOR

Antti Karttunen, Aug 27 2020

STATUS

approved

editing