Pasted from MS Excel...........differences of cubes.........I put a dot next to all the primes.................91 is the 1st non prime..........169 is next............169 is 13 squared.....................91 is the jump in harmonic series................1/1 + 1/2 + 1/3....1/9 + 1/10.............combining numerator and denominator..............becomes........11 + 12 + 13.........19 + 110.....................the jump from 19 to 110 is 91...............................8 out of 10 overlapping differences are primes.....whereas.......u get 7 from squares..............

7	.
19	.
37	.
61	.
91
127	.
169
217	.
271	.
331	.