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 A289190 #22 Sep 08 2022 08:46:19 %S A289190 5,6,14,26,44,46,56,64,74,76,86,94,106,146,154,164,206,226,236,244, %T A289190 254,256,274,286,296,304,314,326,344,346,364,424,436,446,454,464,506, %U A289190 524,536,596,614,664,674,676,686,694,706,764,776,796,826,844,854,874,944,946 %N A289190 Numbers k such that k^2 with last digit deleted is a prime. %H A289190 Marius A. Burtea, <a href="/A289190/b289190.txt">Table of n, a(n) for n = 1..545</a> %e A289190 14 is in the sequence because 14^2 = 196; deleting the last digit gives 19 which is prime. %e A289190 26 is in the sequence because 26^2 = 676; deleting the last digit gives 67 which is prime. %p A289190 select(n -> isprime(floor(n^2/10)),[$1..2000]); %t A289190 fQ[n_] := PrimeQ@Quotient[n^2, 10]; Select[Range[1, 2000], fQ] %o A289190 (Magma) [n : n in [1 .. 2000] | IsPrime (Floor (n^2/10))]; %o A289190 (PARI) isok(n) = isprime(n^2\10); \\ _Michel Marcus_, Jul 02 2017 %Y A289190 Cf. A024770, A031149, A137812, A227916, A227919, A258032. %K A289190 nonn,base %O A289190 1,1 %A A289190 _K. D. Bajpai_, Jun 27 2017