cp's OEIS Frontend

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.

A245357 Number of numbers whose base 5/4 expansion (see A024634) has n digits.

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%I A245357 #19 Aug 11 2023 09:54:22
%S A245357 5,5,5,5,5,10,10,15,15,20,25,30,40,50,60,75,95,120,150,185,235,290,
%T A245357 365,455,570,710,890,1110,1390,1735,2170,2715,3390,4240,5300,6625,
%U A245357 8280,10350,12940,16175,20215,25270,31590,39485,49355,61695,77120,96400,120500
%N A245357 Number of numbers whose base 5/4 expansion (see A024634) has n digits.
%H A245357 <a href="/index/Ba#base_fractional">Index entries for sequences related to fractional bases</a>
%F A245357 a(n) = 5*A120160(n).
%e A245357 The numbers 10..14 are represented by 430, 431, 432, 433, 434 respectively in base 5/4. These are the only numbers with three digits, and so a(3)=5.
%o A245357 (Sage)
%o A245357 A=[1]
%o A245357 for i in [1..60]:
%o A245357     A.append(ceil((5-4)/4*sum(A)))
%o A245357 [5*x for x in A]
%Y A245357 Cf. A024634, A120160, A081848.
%K A245357 nonn,base
%O A245357 1,1
%A A245357 _James Van Alstine_, Jul 18 2014