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A341611 Nonabundant numbers that are not primitive terms of A246282. 3
8, 16, 27, 28, 32, 44, 45, 50, 52, 63, 64, 68, 75, 76, 81, 92, 98, 99, 105, 110, 116, 117, 124, 128, 130, 135, 136, 147, 148, 152, 153, 154, 164, 165, 170, 171, 172, 175, 182, 184, 188, 189, 190, 195, 207, 212, 225, 230, 231, 232, 236, 238, 243, 244, 245, 248, 250, 255, 256, 261, 266, 268, 273, 279, 284, 285, 290, 292, 296, 297 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Terms k of A263837 for which A337345(k) > 1 (or equally, for which A337346(k) > 0).

Numbers k such that sigma(k) <= 2k and k has at least two distinct divisors d such that 2d < A003961(d). By necessity, one of these divisors is then k itself.

LINKS

Table of n, a(n) for n=1..70.

PROG

(PARI)

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

A337345(n) = sumdiv(n, d, A003961(d)>(d+d));

isA341611(n) = ((sigma(n)<=(2*n))&&(1<A337345(n)));

CROSSREFS

Intersection of A341610 and A263837. Subsequence of A341614.

Cf. A000203, A003961, A337345, A337346.

Sequence in context: A302537 A074750 A190519 * A083419 A329134 A090081

Adjacent sequences:  A341608 A341609 A341610 * A341612 A341613 A341614

KEYWORD

nonn

AUTHOR

Antti Karttunen, Feb 22 2021

STATUS

approved

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Last modified May 20 01:04 EDT 2022. Contains 353847 sequences. (Running on oeis4.)