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 A378624 #34 Dec 22 2024 10:31:25 %S A378624 0,5,10,15,19,20,30,38,40,45,49,59,60,65,75,76,80,85,90,95,98,103,105, %T A378624 118,120,125,130,135,137,150,152,157,160,165,170,175,179,180,190,195, %U A378624 196,206,210,215,217,225,235,236,240,245,250,255,259,260,270,274,279,281,289,299 %N A378624 Numbers whose binary representation interpreted as being base-3 is divisible by 5. %C A378624 This sequence is infinite. Given any arbitrarily large number, the last 4 binary bits can be set to 0, and, if this number does not already meet the criteria, one of the last 4 bits can be increased to 1 such that it does. %H A378624 Paolo Xausa, <a href="/A378624/b378624.txt">Table of n, a(n) for n = 1..10000</a> %e A378624 19 is a term: 19 = 10011_2 -> 10011_3 = 85 = 17 * 5. %t A378624 Select[Range[0, 300], Divisible[FromDigits[IntegerDigits[#, 2], 3], 5] &] (* _Paolo Xausa_, Dec 22 2024 *) %o A378624 (PARI) is(n) = fromdigits(binary(n),3)%5 == 0 \\ _David A. Corneth_, Dec 02 2024 %Y A378624 Cf. A001969, A079498. %K A378624 nonn,base %O A378624 1,2 %A A378624 _Kyle David Krueger_, Dec 02 2024