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 A138439 #13 Jun 14 2025 16:19:40 %S A138439 8,81,1250,7203,73205,171366,668168,1172889,3078251,9901934,13852815, %T A138439 33734898,56515220,71794821,112232663,205152506,351403469,415375230, %U A138439 664986993,889408835,1022336676,1519053159,1945791161,2760658604,4249405488,5203020050,5740094931,6947218853 %N A138439 a(n) = (prime(n)^5 - prime(n)^4)/2. %F A138439 a(n) = A138407(n)/2. - _R. J. Mathar_, Oct 15 2017 %p A138439 a:= n-> (p-> p^4*(p-1)/2)(ithprime(n)): %p A138439 seq(a(n), n=1..28); # _Alois P. Heinz_, Jun 14 2025 %t A138439 a[n_]:=(Prime[n]^5-Prime[n]^4)/2; Array[a,24] (* _Stefano Spezia_, Jun 14 2025 *) %o A138439 (PARI) forprime(p=2,1e3,print1((p^5-p^4)/2", ")) \\ _Charles R Greathouse IV_, Jul 15 2011 %Y A138439 Cf. A138407. %K A138439 nonn,easy %O A138439 1,1 %A A138439 _Artur Jasinski_, Mar 19 2008 %E A138439 a(25)-a(28) from _Stefano Spezia_, Jun 14 2025