a(n) = sum_{k=1..n} k*floor(n/k); also sum_{k=1..n} sigma(k) where sigma(n) = sum of divisors of n (A000203).
1, 4, 8, 15, 21, 33, 41, 56, 69, 87, 99, 127, 141, 165, 189, 220, 238, 277, 297, 339
2 seqfan posts
Tue Apr 28 23:15:37 CEST 2009 [seqfan] Re: Typos in comment to A002088 (acuumulating sum of totient(k))