OFFSET
1,1
COMMENTS
For n > 20, a(n) < A370138(n).
LINKS
Antti Karttunen, Table of n, a(n) for n = 1..15180
EXAMPLE
Table T(x,y,z) = A065091(x) * A065091(y) * A065091(z), x >= y >= z >= 1, is read by lexicographical ordering of weakly decreasing triplets (x,y,z):
(1, 1, 1) -> 3*3*3 = 27;
(2, 1, 1) -> 5*3*3 = 45, (2, 2, 1) -> 5*5*3 = 75, (2, 2, 2) -> 5*5*5 = 125;
(3, 1, 1) -> 7*3*3 = 63, (3, 2, 1) -> 7*5*3 = 105, (3, 2, 2) -> 7*5*5 = 175, (3, 3, 1) -> 7*7*3 = 147, (3, 3, 2) -> 7*7*5 = 245, (3, 3, 3) -> 7*7*7 = 343.
MATHEMATICA
Table[Prime[i]*Prime[j]*Prime[k], {i, 2, 8}, {j, 2, i}, {k, 2, j}] // Flatten (* Michael De Vlieger, Mar 09 2024 *)
PROG
(PARI)
up_to = 15180;
A369979list(up_to) = { my(v = vector(up_to), i=0); for(x=1, oo, for(y=1, x, for(z=1, y, i++; if(i > up_to, return(v)); v[i] = prime(1+x)*prime(1+y)*prime(1+z)))); (v); };
v369979 = A369979list(up_to);
A369979(n) = v369979[n];
CROSSREFS
KEYWORD
nonn,tabf
AUTHOR
Antti Karttunen, Mar 09 2024
STATUS
approved