You wrote > Additional elements: > > 0 56 147 238 329 560 651 742 798 833 889 924 1001 1057 1148 1239 1470 > 1561 1652 1743 1799 1834 1925 2002 2058 2149 2380 2471 2562 2653 2744 Well, the 1st differences so far consist of a sequence containing only the numbers 7*5, 7*8, 7*11, 7*13, and 7*33.