cp's OEIS Frontend

A262392 a(n) = A007504(n) + A010693(n).

%I A262392 #29 Oct 11 2015 09:38:38
%S A262392 2,5,7,13,19,31,43,61,79,103,131,163,199,241,283,331,383,443,503,571,
%T A262392 641,715,793,877,965,1063,1163,1267,1373,1483,1595,1723,1853,1991,
%U A262392 2129,2279,2429,2587,2749,2917,3089,3269,3449,3641,3833,4031,4229
%N A262392 a(n) = A007504(n) + A010693(n).
%C A262392 Sequence is interesting because of the fact that a(n) is a prime number for n = 0..20.
%C A262392 Main inspiration of sequence was indices of prime numbers in A036439 and A227547.
%F A262392 a(n) = Sum_{k=1..n} prime(k) + n mod 2 + 2 for n>0, a(0)=2 (from Pari code).
%e A262392 a(0) = A007504(0) + A010693(0) = 0 + 2 = 2.
%e A262392 a(1) = A007504(1) + A010693(1) = 2 + 3 = 5.
%e A262392 a(2) = A007504(2) + A010693(2) = 5 + 2 = 7.
%e A262392 a(3) = A007504(3) + A010693(3) = 10 + 3 = 13.
%e A262392 a(4) = A007504(4) + A010693(4) = 17 + 2 = 19.
%e A262392 a(5) = A007504(5) + A010693(5) = 28 + 3 = 31.
%t A262392 s = Accumulate@ Prime@ Range@ 1200; {2}~Join~Table[s[[n]] + If[OddQ@ n, 3, 2], {n, 46}] (* _Michael De Vlieger_, Sep 21 2015 *)
%o A262392 (PARI) a(n) = sum(k=1, n, prime(k)) + (n%2) + 2;
%o A262392 vector(50, n, a(n-1))
%Y A262392 Cf. A036439, A227547, A007504, A010693, A071148.
%K A262392 nonn,easy
%O A262392 0,1
%A A262392 _Altug Alkan_, Sep 21 2015