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 A137831 #10 Jun 03 2025 11:13:04 %S A137831 0,0,1,2,6,8,14,18,26,42,48,68,84,92,110,140,174,186,224,252,266,312, %T A137831 344,396,470,510,530,572,594,638,806,858,938,966,1110,1140,1232,1328, %U A137831 1394,1496,1602,1638,1824,1862,1940,1980,2226,2486,2576,2622,2714,2856 %N A137831 a(n) = (prime(n)^2 minus its last digit)/20. %F A137831 a(n) = (A001248(n)-A137807(n))/20. - _R. J. Mathar_, May 23 2008 %p A137831 a:= n-> iquo(ithprime(n)^2, 10)/2: %p A137831 seq(a(n), n=1..52); # _Alois P. Heinz_, Jun 03 2025 %t A137831 a[n_]:=(Prime[n]^2-Mod[Prime[n]^2,10])/20;Array[a,52] (* _James C. McMahon_, Jun 03 2025 *) %Y A137831 Cf. A001248, A137807. %K A137831 nonn,base,easy %O A137831 1,4 %A A137831 _Paul Curtz_, Apr 29 2008 %E A137831 More terms from _R. J. Mathar_, May 23 2008