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 A385701 #16 Jul 08 2025 14:15:16 %S A385701 0,6,21,24,27,42,45,48,60,63,66,69,81,84,87,201,204,207,210,213,216, %T A385701 219,222,225,228,231,234,237,240,243,246,249,252,255,258,261,264,267, %U A385701 270,273,276,279,282,285,288,291,294,297,402,405,408,411,414,417,420,423,426,429 %N A385701 Numbers such that when the leftmost digit is moved to the unit's place the result is divisible by 6. %H A385701 Stefano Spezia, <a href="/A385701/b385701.txt">Table of n, a(n) for n = 1..10000</a> %e A385701 426 is a term since 264 = 44*6 is divisible by 6. %t A385701 Select[Range[0,430],Divisible[FromDigits[RotateLeft[IntegerDigits[#]]],6] &] %o A385701 (PARI) isok(k) = if (k==0, return(1)); my(d=digits(k), v = vector(#d-1, i, d[i+1])); v = concat(v, d[1]); fromdigits(v) % 6 == 0; \\ _Michel Marcus_, Jul 08 2025 %o A385701 (Python) %o A385701 def ok(n): return int((s:=str(n))[1:]+s[0])%6 == 0 %o A385701 print([k for k in range(430) if ok(k)]) # _Michael S. Branicky_, Jul 08 2025 %Y A385701 Similar sequences for k=1..9: A001477, A273892, A008585, A385700, A217398, this sequence, A385702, A385703, A008591. %K A385701 nonn,base,easy,look %O A385701 1,2 %A A385701 _Stefano Spezia_, Jul 07 2025