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 A079477 #12 Mar 15 2023 12:22:06 %S A079477 3,7,23,43,113,157,277,347,509,821,937,1361,1657,1811,2179,2767,3433, %T A079477 3671,4423,4973,5261,6163,6823,7841,9319,10103,10513,11351,11777, %U A079477 12659,16007,17033,18637,19183,22063,22651,24499,26407,27733,29759,31873,32587,36293 %N A079477 First prime after phi(prime(n)^2). %C A079477 The sequence always increases. %H A079477 G. C. Greubel, <a href="/A079477/b079477.txt">Table of n, a(n) for n = 1..10000</a> %F A079477 a(n) = A151800(A036689(n)). - _Michel Marcus_, Mar 15 2023 %e A079477 p_3=5, phi(5^2)=phi(25)=20, therefore a(3)=23 %p A079477 a:= n-> nextprime(2*binomial(ithprime(n),2)): %p A079477 seq(a(n), n=1..44); # _Alois P. Heinz_, Mar 15 2023 %t A079477 Prime[1+PrimePi[EulerPhi[Prime[Range[41]]^2]]] (* _T. D. Noe_, Nov 15 2006 *) %o A079477 (PARI) forprime (p=2,200, print1(nextprime(eulerphi(p^2))",")) %Y A079477 Cf. A036689, A151800. %K A079477 nonn %O A079477 1,1 %A A079477 _Jon Perry_, Jan 15 2003 %E A079477 Corrected by _T. D. Noe_, Nov 15 2006