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 A278914 #34 Aug 08 2025 14:21:22
%S A278914 9,2401,729,9765625,531441,45949729863572161,5559917313492231481,
%T A278914 1471383076677527699142172838322885948765175969,
%U A278914 10264895304762966931257013446474591264089923314972889033759201,230466617897195215045509519405933293401
%N A278914 a(n) is the smallest odd number k with prime sum of divisors such that tau(k) = n-th prime.
%C A278914 tau(n) = A000005(n) = the number of divisors of n.
%C A278914 For n >= 7; a(n) > A023194(10000) = 5896704025969.
%H A278914 Robert G. Wilson v, <a href="/A278914/b278914.txt">Table of n, a(n) for n = 2..66</a> (first 49 terms from Davin Park)
%F A278914 a(n) = A101636(n)^(prime(n)-1). - _Davin Park_, Dec 10 2016
%e A278914 a(2) = 9 because 9 is the smallest odd number with prime values of sum of divisors (sigma(9) = 13) such that tau(9) = 3 = 2nd prime.
%t A278914 A278914[n_] := NestWhile[NextPrime, 3, ! PrimeQ[Cyclotomic[Prime[n], #]] &]^(Prime[n] - 1); Array[A278914, 10, 2] (* _Davin Park_, Dec 28 2016 *)
%o A278914 (Magma) A278914:=func<n|exists(r){k:k in[1..10000000] | IsOdd(k) and IsPrime(SumOfDivisors(k)) and NumberOfDivisors(k) eq NthPrime(n)} select r else 0>; [A278914(n): n in[2..6]];
%o A278914 (PARI) a(n) = {my(k=1); while(! (isprime(sigma(k)) && isprime(p=numdiv(k)) && (primepi(p) == n)), k+=2); k;} \\ _Michel Marcus_, Dec 03 2016
%Y A278914 Cf. A000005, A000203, A278911, A278913.
%K A278914 nonn
%O A278914 2,1
%A A278914 _Jaroslav Krizek_, Nov 30 2016
%E A278914 More terms from _Davin Park_, Dec 11 2016