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A364964
Numbers k such that k is a multiple of A243071(k).
2
2, 3, 4, 6, 8, 12, 16, 24, 27, 32, 48, 54, 64, 96, 108, 128, 192, 216, 256, 315, 384, 432, 512, 630, 768, 864, 1024, 1260, 1536, 1728, 2048, 2520, 3003, 3072, 3456, 4096, 5040, 6006, 6144, 6912, 8192, 10080, 12012, 12288, 13824, 16384, 20160, 24024, 24576, 27648, 32768, 40320, 42757, 48048, 49152, 55296, 65536
OFFSET
1,1
COMMENTS
For k > 1, if k is a term, then also 2*k is present in this sequence, and vice versa.
PROG
(PARI)
A243071(n) = if(n<=2, n-1, my(f=factor(n), p, p2=1, res=0); for(i=1, #f~, p = 1 << (primepi(f[i, 1]) - 1); res += (p*p2*(2^(f[i, 2]) - 1)); p2 <<= f[i, 2]); ((3<<#binary(res\2))-res-1)); \\ (Combining programs given in A156552 and A054429)
isA364964(n) = ((n>1)&&!(n%A243071(n)));
CROSSREFS
Sequence A163511(A364494(n)), for n>=0, sorted into ascending order.
Cf. A007283 (subsequence), A364965 (odd terms).
Cf. also A364497, A364550.
Sequence in context: A241344 A064428 A052810 * A320315 A364956 A164090
KEYWORD
nonn
AUTHOR
Antti Karttunen, Sep 01 2023
STATUS
approved