



 
Hi John. Begin with (n+1)^{3}/3 + (n+1)^{5}/5 + 7(n+1)/15 = (1/3)( n^{3} + 3n^{2} + 3n + 1) + (1/5)(n^{5} + 5n^{4} + 10n^{3} + 10n^{2} + 5n + 1) + 7n/15 + 7/15 and you have to demonstrate that the rest is an integer. Can you finish the algebra? Cheers,  


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