login

Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 61st year, we have over 378,000 sequences, and we’ve reached 11,000 citations (which often say “discovered thanks to the OEIS”).

A347250
Numbers k for which A331410(k) < A336361(k).
2
9, 17, 18, 34, 36, 49, 67, 68, 71, 72, 81, 97, 98, 134, 136, 142, 144, 147, 162, 193, 194, 196, 268, 271, 272, 283, 284, 288, 291, 293, 294, 324, 386, 388, 392, 536, 541, 542, 544, 566, 568, 576, 579, 582, 586, 587, 588, 647, 648, 679, 772, 776, 784, 961, 1072, 1082, 1084, 1087, 1088, 1132, 1136, 1151, 1152, 1158, 1163
OFFSET
1,1
COMMENTS
If k is a term, then also 2*k is present in this sequence.
PROG
(PARI)
A331410(n) = { my(f=factor(n)); sum(k=1, #f~, if(2==f[k, 1], 0, f[k, 2]*(1+A331410(f[k, 1]+1)))); };
A336361(n) = if(!bitand(n, n-1), 0, 1+A336361(sigma(n>>valuation(n, 2))));
A347249(n) = (A331410(n)-A336361(n));
isA347250(n) = (A347249(n)<0);
CROSSREFS
Positions of negative terms in A347249.
Sequence in context: A224442 A343111 A364540 * A192049 A133246 A190151
KEYWORD
nonn
AUTHOR
Antti Karttunen, Aug 28 2021
STATUS
approved