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In my work on number of partitions of natural numbers in parts non greater than 5 arise the sequence $775,1015,1285,1585,1915,2275,2665,3085,3535,4015,4525,5065,5635,6235,6865,7525,8215,8935,9685$ I now first 60 terms of this sequence and all can be divided by 5. Any help on general term.

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    775 is first term of an additional sequence that arise in context.2011-08-07

1 Answers 1

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Hint: Consider the corresponding sequence of differences: $240,270,300,330,\ldots$.

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    Using this hint you can find that $a_n = 5(3n^2 + 39n + 113)$, $n \geq 1$.2011-08-07