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A337380 a(n) = 1 if A003961(n) > 2*sigma(n), 0 otherwise. 4
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 1, 0, 0, 0, 0, 1, 0, 0, 0, 1, 0, 0, 0, 1, 0, 0, 0, 0, 1, 0, 0, 1, 1, 0, 0, 0, 0, 1, 0, 1, 0, 0, 0, 0, 0, 0, 1, 1, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 1, 1, 0, 0, 1, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 1, 0, 1, 1, 1, 0, 0, 0, 1, 1 (list; graph; refs; listen; history; text; internal format)
OFFSET
1
LINKS
PROG
(PARI)
A003961(n) = { my(f = factor(n)); for (i=1, #f~, f[i, 1] = nextprime(f[i, 1]+1)); factorback(f); };
A337380(n) = (A003961(n)>2*sigma(n));
CROSSREFS
Characteristic function of A337378.
Cf. also A252742, A337383.
Sequence in context: A358261 A295884 A101637 * A011729 A297044 A296213
KEYWORD
nonn
AUTHOR
Antti Karttunen, Aug 27 2020
STATUS
approved

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Last modified April 23 23:26 EDT 2024. Contains 371917 sequences. (Running on oeis4.)