|
|
A306044
|
|
Powers of 2, 3 and 5.
|
|
4
|
|
|
1, 2, 3, 4, 5, 8, 9, 16, 25, 27, 32, 64, 81, 125, 128, 243, 256, 512, 625, 729, 1024, 2048, 2187, 3125, 4096, 6561, 8192, 15625, 16384, 19683, 32768, 59049, 65536, 78125, 131072, 177147, 262144, 390625, 524288, 531441, 1048576, 1594323, 1953125, 2097152, 4194304, 4782969, 8388608
(list;
graph;
refs;
listen;
history;
text;
internal format)
|
|
|
OFFSET
|
1,2
|
|
COMMENTS
|
|
|
LINKS
|
|
|
FORMULA
|
|
|
MAPLE
|
N:= 10^7: # for terms <= N
sort(convert(`union`(seq({seq(b^i, i=0..ilog[b](N))}, b=[2, 3, 5])), list)); # Robert Israel, Nov 18 2022
|
|
MATHEMATICA
|
Union[2^Range[0, Log2[5^10]], 3^Range[Log[3, 5^10]], 5^Range[10]]
|
|
PROG
|
(PARI) setunion(setunion(vector(logint(N=10^6, 5)+1, k, 5^(k-1)), vector(logint(N, 3), k, 3^k)), vector(logint(N, 2), k, 2^k)) \\ M. F. Hasler, Jun 24 2018
(PARI) a(n)= my(f=[2, 3, 5], q=sum(k=1, #f, 1/log(f[k]))); for(i=1, #f, my(p=logint(exp(n/q), f[i]), d=0, j=0, m=0); while(j<n, m=f[i]^(p+d); j=1+sum(k=1, #f, logint(m, f[k])); if(j==n, return(m)); d++)) \\ Ruud H.G. van Tol, Nov 16 2022 (with the help of the pari-users mailing list) Observation: with f=primes(P), d <= logint(P, 2).
|
|
CROSSREFS
|
|
|
KEYWORD
|
nonn
|
|
AUTHOR
|
|
|
STATUS
|
approved
|
|
|
|