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 A195607 #17 Apr 14 2023 17:42:02 %S A195607 1,8,161,809,809,161803,1618033,16180339,80901699,404508497, %T A195607 16180339887,80901699437,1618033988749,8090169943749,161803398874989, %U A195607 809016994374947,4045084971874737,40450849718747371,25281781074217107,8090169943749474241 %N A195607 Numerator of floor(Phi*10^n)/10^n, where phi = (sqrt(5) + 1)/2 = A001622 is the Golden Ratio. %C A195607 Numerator of the decimal fraction of phi = 1.61803... truncated to a given number of decimal places. %C A195607 The corresponding sequence for 1/phi = 0.61803... = phi-1 (also called the Golden Ratio) has a very similar behavior, because for both, the truncated decimal expansion can be simplified by the same factors 2^k*5^m. %e A195607 a(3) = 161 is the numerator of 1.61 = 161/100. %e A195607 a(4) = 809 is the numerator of 1.618 = 1618/1000 = 809/500. %t A195607 Floor[GoldenRatio #]/#&/@(10^Range[0,20])//Numerator (* _Harvey P. Dale_, Apr 14 2023 *) %o A195607 (PARI) a(n,c=sqrt(5)/2+.5)=numerator(c\.1^n/10^n) \\ _M. F. Hasler_, Sep 21 2011 %Y A195607 Cf. A001622, A011551. %Y A195607 Cf. A195603 (analog for Pi), A195604 (for e), A195606 (for gamma). %K A195607 nonn,base %O A195607 0,2 %A A195607 _M. F. Hasler_, following a suggestion by _Eric Angelini_, Sep 21 2011