OFFSET
1,1
COMMENTS
The oblong number (k^2+2*k)*(k^2+2*k+1) = A047928(k+2) is a term for all k >= 1, because it is the product of the oblong numbers k*(k+1) and (k+1)*(k+2).
EXAMPLE
72 is a term because 72 = 8*9 = 6*12 = (2*3)*(3*4).
1056 is a term because 1056 = 32*33 = 2*2*2*132 = (1*2)*(1*2)*(1*2)*(11*12). (This is the first term that requires more than two factors.)
CROSSREFS
KEYWORD
nonn
AUTHOR
Pontus von Brömssen, Jul 07 2024
STATUS
approved