A204890 - OEIS

%I #19 May 22 2016 00:03:12

%S 1,3,2,5,4,2,9,8,6,4,11,10,8,6,2,15,14,12,10,6,4,17,16,14,12,8,6,2,21,

%T 20,18,16,12,10,6,4,27,26,24,22,18,16,12,10,6,29,28,26,24,20,18,14,12,

%U 8,2,35,34,32,30,26,24,20,18,14,8,6,39,38,36,34,30,28,24,22

%N Ordered differences of primes.

%C For a guide to related sequences, see A204892.

%C A086800, zeros omitted. - _R. J. Mathar_, Sep 15 2012

%e a(1) = p(2)-p(1) = 3-2 = 1

%e a(2) = p(3)-p(1) = 5-2 = 3

%e a(3) = p(3)-p(2) = 5-3 = 2

%e a(4) = p(4)-p(1) = 7-2 = 5

%e a(5) = p(4)-p(2) = 7-3 = 4

%e a(6) = p(4)-p(3) = 7-5 = 2

%e From _Michel Marcus_, May 12 2016: (Start)

%e As a triangle, first rows are:

%e 1;

%e 3, 2;

%e 5, 4, 2;

%e 9, 8, 6, 4;

%e 11, 10, 8, 6, 2;

%e (End)

%t (See the program at A204892.)

%t With[{prs=Prime[Range[20]]},Flatten[Table[prs[[n]]-Take[prs,n-1], {n,2,Length[prs]}]]] (* _Harvey P. Dale_, Dec 01 2013 *)

%o (PARI) tabl(nn) = {for (n=2, nn, for (m=1, n-1, print1(prime(n) - prime(m), ", ");); print(););} \\ _Michel Marcus_, May 12 2016

%Y Cf. A204892, A090321.

%K nonn,tabl,easy

%O 1,2

%A _Clark Kimberling_, Jan 20 2012