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 A276654 #29 Sep 08 2022 08:46:17 %S A276654 2,21,2905,281785,47740490,9178864590,8533159052845,1817562878255985, %T A276654 1801204812351681135,787408225243814333670 %N A276654 a(n) = the smallest number k>1 such that floor(Sum_{p|k} 0.p) = n where p runs through the prime divisors of k. %C A276654 Here 0.p means the decimal fraction obtained by writing p after the decimal point, e.g. 0.11 = 11/100. %C A276654 The first few values of Sum_{p|n} 0.p are: 1/5, 3/10, 1/5, 1/2, 1/2, 7/10, 1/5, 3/10, 7/10, ... %C A276654 Subsequence of A005117. - _Chai Wah Wu_, Sep 15 2016 %e A276654 Number 2905 is the smallest number k with floor(Sum_{p|k} 0.p) = 2; set of prime divisors of 2905: {5, 7, 83}; floor(Sum_{p|2905} 0.p) = 0.5 + 0.7 + 0.83 = floor(2.03) = 2. %t A276654 Table[k = 2; While[f = FactorInteger[k][[All, 1]]; %t A276654 Floor[Total[f*10^-IntegerLength[f]]] != n, k++]; %t A276654 k, {n, 0, 3}] (* _Robert Price_, Sep 20 2019 *) %o A276654 (Magma) A276654:=func<n|exists(r){k:k in[2..1000000] | Floor(&+[d / (10^(#Intseq(d))): d in PrimeDivisors(k)]) eq n}select r else 0>; [A276654(n): n in[0..3]] %Y A276654 Cf. A005117, A276513, A276651, A276652, A276653, A276655. %K A276654 nonn,base,more %O A276654 0,1 %A A276654 _Jaroslav Krizek_, Sep 11 2016 %E A276654 a(4) from _Michel Marcus_, Sep 11 2016 %E A276654 a(5)-a(9) from _Giovanni Resta_, Aug 31 2019