A134651 - OEIS

%I #9 Oct 15 2013 02:15:10

%S 10,13,16,17,20,23,24,26,29,30,32,35,36,38,41,42,44,47,48,50,54,57,60,

%T 64,65,66,68,70,72,73,76,78,80,82,83,84,86,88,89,90,92,94,95,96,98,

%U 102,104,105,108,110,112,114,117,118,120,124,125,126,128,130,132,133,136,138,140

%N Numbers which are the sum of two terms from A001043.

%H B. D. Swan, <a href="/A134651/b134651.txt">Table of n, a(n) for n=1,...,60000</a>

%e Recall that A001043 begins with 5,8,12, ..

%e So 10 (5+5), 13 (5+8), 16 (8+8), 17 (5+12), 20 (8+12) are in the sequence.

%o (PARI) issum(i, vss) = {for (j = 1, #vss, if (vss[j] > i, break); for (k = 1, #vss, sv = vss[j] + vss[k]; if (sv == i, return (1)); if (sv > i, break););); return (0);}

%o lista(nn) = {vec = vector(nn, i, i); vss = select(i->((precprime((i-1)/2) + nextprime(i/2) == i) && (i>2)), vec); for (i = 1, nn, if (issum(i, vss), print1(i, ", ")););} \\ _Michel Marcus_, Oct 14 2013

%Y Cf. A001043, A134650.

%K nonn,easy

%O 1,1

%A _N. J. A. Sloane_, Jan 25 2008