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A191367
a(n) is the smallest sum of 2 distinct positive cubes such that n*a(n) is also sum of 2 distinct positive cubes.
1
9, 728, 2457, 189, 189, 126, 91, 9, 1001, 28, 91, 126, 133, 9, 2331, 91, 91, 189, 91, 854, 9, 133, 133, 2457, 217, 28, 9, 126, 217, 468, 133, 189, 3528, 11772, 637, 28, 133, 28, 9, 189, 637, 468, 217, 559, 152, 637, 559, 126, 72, 637, 5256, 9, 793, 28, 793
OFFSET
1,1
COMMENTS
a(n) and n*a(n) are terms of A024670 (Numbers that are sums of 2 distinct positive cubes); a(n)=9 if n is in A191352.
FORMULA
a(n)=b^3+c^3, n*a(n)=d^3+e^3.
EXAMPLE
{n,a(n),b,c,n*a(n),d,e}={1,9,1,2,9,1,2},{2,728,6,8,1456,5,11},{3,2457,9,12,7371,8,19},...
CROSSREFS
Sequence in context: A120816 A161585 A255259 * A189821 A053933 A145262
KEYWORD
nonn
AUTHOR
Zak Seidov, Jun 01 2011
STATUS
approved