The first number is 3 and the next number following 515 is 732.
Series: 3, 4, 11, 30, 67, 128, 219, 346, 515, 732
1st diff:...1...7..19..37..61....91...127..169...217
2nd diff:.....6..12 18..24...30....36....42.....48 consecutive multiples of 6 starting at 1.