This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A090482 #7 Aug 03 2014 14:01:20
%S A090482 0,0,2,0,3,0,5,7,0,11,17,19,37,29,0,41,101,79,0,71,197,179,401,199,
%T A090482 2917,181,577,239,3137,883,4357,419,1297,701,12101,839,62501,881,
%U A090482 30977,1429,21317,2351,16901,1259,287297,1871,1008017,2161,7057,4049,215297,3079
%N A090482 Smallest prime p such that tau(p-1) + tau(p+1) is n, or 0 if no such number exists.
%C A090482 a(9)=0. Proof: Both p-1 and p+1 are even and composite hence 9=1+8 and 9=2+7 are ruled out, the only possibilities that remain are 9 = 3+6, or 9=4+5. 3+6 is ruled out as 4 is the only even number with 3 divisors. 4+5 is ruled out as 16 is the only even number with 5 divisors.
%C A090482 a(15) = a(19) = 0 is also provable. - _David Wasserman_, Nov 17 2005
%F A090482 Least prime p such that A175144(p) = n.
%e A090482 a(10) = 11, tau(10) = 4 and tau(12) = 6, 4+6=10.
%e A090482 a(16) = 41, a(17) = 101.
%t A090482 nn = 60; t = Table[-1, {nn}]; t[[{1,2,4,6,9,15,19}]] = 0; cnt = 7; p = 1; While[cnt < nn, p = NextPrime[p]; s = DivisorSigma[0, p-1] + DivisorSigma[0, p+1]; If[s <= nn && t[[s]] == -1, t[[s]] = p; cnt++]]; t (* _T. D. Noe_, Apr 28 2011 *)
%Y A090482 Cf. A090481, A090483, A175144.
%K A090482 nonn
%O A090482 1,3
%A A090482 _Amarnath Murthy_, Dec 02 2003
%E A090482 More terms from _David Wasserman_, Nov 17 2005