cp's OEIS Frontend

A086800 Triangle read by rows in which row n lists differences between prime(n) and prime(k) for 1 <= k <= n.

%I A086800 #14 Jun 17 2025 09:20:57
%S A086800 0,1,0,3,2,0,5,4,2,0,9,8,6,4,0,11,10,8,6,2,0,15,14,12,10,6,4,0,17,16,
%T A086800 14,12,8,6,2,0,21,20,18,16,12,10,6,4,0,27,26,24,22,18,16,12,10,6,0,29,
%U A086800 28,26,24,20,18,14,12,8,2,0,35,34,32,30,26,24,20,18,14,8,6,0
%N A086800 Triangle read by rows in which row n lists differences between prime(n) and prime(k) for 1 <= k <= n.
%C A086800 Primes in this sequence are of course twin primes.
%H A086800 Michel Marcus, <a href="/A086800/b086800.txt">Rows n=1..100 of triangle, flattened</a>
%e A086800 2-2=0; 3-2=1, 3-3=0; 5-2=3, 5-3=2, 5=5=5; 7-2=5, 7-3=4, 7-5=2, 7-7=0, ...
%e A086800 Triangle begins:
%e A086800   0;
%e A086800   1, 0;
%e A086800   3, 2, 0;
%e A086800   5, 4, 2, 0;
%e A086800   9, 8, 6, 4, 0;
%e A086800   11, 10, 8, 6, 2, 0;
%e A086800   15, 14, 12, 10, 6, 4, 0;
%e A086800   17, 16, 14, 12, 8, 6, 2, 0;
%o A086800 (PARI) fn(n) = forprime(x=2,n, forprime(y=2,x,print1(x-y",")))
%o A086800 (PARI) T(n, k) = prime(n) - prime(k);
%o A086800 tabl(nn) = for (n=1, nn, for (k=1, n, print1(T(n, k), ", ")); print); \\ _Michel Marcus_, Aug 08 2017
%Y A086800 Cf. A040976 (1st column).
%K A086800 easy,tabl,nonn
%O A086800 1,4
%A A086800 _Cino Hilliard_, Aug 05 2003
%E A086800 Offset corrected by _Michel Marcus_, Aug 08 2017