

A343926


a(n) is the least k such that A343443(k) = n or 0 if there is no such k.


1



1, 0, 2, 4, 8, 16, 32, 64, 6, 256, 512, 12, 2048, 4096, 24, 36, 32768, 48, 131072, 72, 96, 1048576, 2097152, 144, 216, 16777216, 30, 288, 134217728, 432, 536870912, 576, 1536, 4294967296, 864, 60, 34359738368, 68719476736, 6144, 1728, 549755813888, 2592, 2199023255552
(list;
graph;
refs;
listen;
history;
text;
internal format)



OFFSET

1,3


COMMENTS

The indices for which a(n)=2^(n2) appear to be A232803.  Michel Marcus, May 05 2021
This is true. We can check it for n <= 10. For n > 10 there are only primes and twice primes in A232803. Any number k > 10 not in A232803 can be factored as k = m*p where m, p > 2 and m >= p. We then have A343443(2^(m2)*3^(p2)) = m*p = k. But 2^(k2) = 2^(m*p2) > 2^(m2)*3^(p2). As m, p > 2 we have 2^(m2)*3^(p2) not in A232803.  David A. Corneth, May 05 2021


LINKS

David A. Corneth, Table of n, a(n) for n = 1..3325 (first 52 terms from Michel Marcus).


FORMULA

a(n) <= 2^(n2) for n>=3.


CROSSREFS

Cf. A025487, A232803, A343443.
Sequence in context: A025489 A160686 A201920 * A223700 A036140 A036138
Adjacent sequences: A343921 A343922 A343923 * A343927 A343928 A343929


KEYWORD

nonn


AUTHOR

Michel Marcus, May 04 2021


STATUS

approved



