|
%I #6 Nov 12 2017 03:02:44
%S 6,6,8,9,14,15,20,21,25,32,33,39,44,45,49,55,62,63,69,74,75,81,85,91,
%T 99,104,105,110,111,115,129,133,140,141,152,153,159,165,169,175,182,
%U 183,194,195,200,201,213,225,230,231,235,242,243,253,259,265,272,273,279
%N The second nonprimes after the primes.
%F a(n) = prime(n)+2 + A010051(prime(n)+1) + A010051(prime(n)+2) + A010051(prime(n)+3). [From _Reinhard Zumkeller_, Mar 29 2010]
%t b[n_] := Boole[PrimeQ[n]];
%t a[n_] := With[{p = Prime[n]}, p + 2 + b[p + 1] + b[p + 2] + b[p + 3]];
%t Array[a, 59] (* _Jean-François Alcover_, Nov 12 2017, after _Reinhard Zumkeller_ *)
%K nonn,easy
%O 1,1
%A _Jaroslav Krizek_, Mar 06 2010
%E More terms from _Reinhard Zumkeller_, Mar 29 2010
%E Typos in data corrected by _Jean-François Alcover_, Nov 12 2017
|
