A066751 - OEIS

%I #10 Dec 15 2017 17:35:48

%S 3,91,136,325,703,1081,1378,1711,3655,11026,11476,13861,18145,18721,

%T 36046,70876,75466,76636,79003,92665,99235,107416,108811,110215,

%U 118828,123256,130816,137026,140185,158203,166753,173755,186355,303031,310078

%N Triangular numbers whose reverse is prime.

%H Harry J. Smith, <a href="/A066751/b066751.txt">Table of n, a(n) for n = 1..1000</a>

%o (PARI) Rev(x)= { local(d, r=0); while (x>0, d=x%10; x\=10; r=r*10 + d); return(r) } { n=0; for (m=1, 10^10, t=m*(m + 1)/2; if (t%10 && isprime(Rev(t)), write("b066751.txt", n++, " ", t); if (n==1000, return)) ) } \\ _Harry J. Smith_, Mar 21 2010

%K easy,nonn,base

%O 1,1

%A _Jason Earls_, Jan 16 2002