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A337379 Numbers k for which A003961(k) < 2*sigma(k). 4
1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 17, 18, 19, 20, 21, 22, 23, 25, 26, 28, 29, 30, 31, 33, 34, 35, 37, 38, 39, 41, 42, 43, 44, 46, 47, 50, 51, 52, 53, 55, 57, 58, 59, 60, 61, 62, 65, 66, 67, 68, 69, 70, 71, 73, 74, 75, 76, 77, 78, 79, 82, 83, 85, 86, 87, 88, 89, 91, 92, 93, 94, 95, 97, 101, 102, 103 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

LINKS

Antti Karttunen, Table of n, a(n) for n = 1..20000

Index entries for sequences computed from indices in prime factorization

Index entries for sequences related to sigma(n)

PROG

(PARI)

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

isA337379(n) = (A003961(n)<2*sigma(n));

CROSSREFS

Cf. A000203, A003961, A286385.

Cf. A337378 (complement).

Positions of zeros in A337380.

Cf. also A246281, A337382 (subsequences).

Sequence in context: A119675 A253781 A037144 * A121684 A191853 A123093

Adjacent sequences:  A337376 A337377 A337378 * A337380 A337381 A337382

KEYWORD

nonn

AUTHOR

Antti Karttunen, Aug 27 2020

STATUS

approved

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Last modified August 12 23:52 EDT 2022. Contains 356077 sequences. (Running on oeis4.)