OFFSET
1,1
COMMENTS
Is this a subsequence of A046034?
FORMULA
A001222(a(n)) = n.
EXAMPLE
a(5) = 22232 because 22232 is the concatenation of the 5 primes 2, 2, 2, 3, 2 and 22232 = 2^3 * 7 * 397 is the product of 5 primes (counted with multiplicity).
MAPLE
f:= proc(n) local k, x, W, L, i;
W:= [2, 3, 5, 7];
for k from 0 to 4^n-1 do
L:= convert(4^n+k, base, 4);
x:= add(W[L[i]+1]*10^(i-1), i=1..n);
if numtheory:-bigomega(x) = n then return x fi;
od;
end proc:
map(f, [$1..20]);
CROSSREFS
KEYWORD
nonn,base
AUTHOR
Robert Israel, Jul 15 2024
STATUS
approved