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A275988
a(n) = prime(3n) - prime(n).
0
3, 10, 18, 30, 36, 48, 56, 70, 80, 84, 106, 114, 126, 138, 150, 170, 174, 190, 202, 210, 234, 238, 264, 270, 282, 296, 316, 326, 340, 350, 360, 372, 386, 418, 422, 442, 450, 456, 476, 486, 498, 520, 536, 550, 564, 588, 600, 604, 626, 634, 650, 672, 696, 702, 720, 734, 750, 762, 774
OFFSET
1,1
FORMULA
a(n) = A031336(n) - A000040(n).
EXAMPLE
For n=3, prime(3n) = 23, and prime(n) = 5, therefore a(3) = 23 - 5 = 18.
MATHEMATICA
Table[Prime[3n] - Prime[n], {n, 1, 100}]
PROG
(PARI) a(n) = prime(3*n) - prime(n); \\ Michel Marcus, Aug 18 2016
CROSSREFS
KEYWORD
nonn
AUTHOR
Terry D. Grant, Aug 15 2016
STATUS
approved