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 A079092 #13 Apr 07 2025 09:51:22 %S A079092 2,2,4,8,12,36,24,32,48,64,144,216,120,160,216,216,240,480,384,432, %T A079092 576,384,432,1008,1344,768,864,720,1440,1152,1280,1320,1056,1200,1440, %U A079092 2808,3120,1920,2016,2016,1728,2304,3072,5760,2400,4160,4992,3456,3168,6336 %N A079092 Euler's totient of (prime(n)+1)*(prime(n+1)+1)/4. %H A079092 Reinhard Zumkeller, <a href="/A079092/b079092.txt">Table of n, a(n) for n = 1..10000</a> %F A079092 a(n) = A000010(A079079(n)). %t A079092 a[n_] := EulerPhi[(Prime[n]+1) * (Prime[n+1]+1) / 4]; Array[a, 100] (* _Amiram Eldar_, Apr 06 2025 *) %o A079092 (Haskell) %o A079092 a079092 = a000010 . a079079 -- _Reinhard Zumkeller_, Oct 09 2012 %o A079092 (PARI) a(n) = eulerphi((prime(n)+1)*(prime(n+1)+1)/4); \\ _Amiram Eldar_, Apr 06 2025 %Y A079092 Cf. A000010, A079079. %K A079092 nonn %O A079092 1,1 %A A079092 _Reinhard Zumkeller_, Dec 22 2002