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 A008963 #43 Aug 25 2025 17:35:38
%S A008963 0,1,1,2,3,5,8,1,2,3,5,8,1,2,3,6,9,1,2,4,6,1,1,2,4,7,1,1,3,5,8,1,2,3,
%T A008963 5,9,1,2,3,6,1,1,2,4,7,1,1,2,4,7,1,2,3,5,8,1,2,3,5,9,1,2,4,6,1,1,2,4,
%U A008963 7,1,1,3,4,8,1,2,3,5,8,1,2,3,6,9,1,2,4,6,1,1,2,4,7,1,1,3,5,8,1
%N A008963 Initial digit of Fibonacci number F(n).
%C A008963 Benford's law applies since the Fibonacci sequence is of exponential growth: P(d)=log_10(1+1/d), in fact among first 5000 values the digit d=1 appears 1505 times, while 5000*P(1) is about 1505.15. - _Carmine Suriano_, Feb 14 2011
%C A008963 Wlodarski observed and Webb proved that the distribution of terms of this sequence follows Benford's law. - _Amiram Eldar_, Sep 23 2019
%H A008963 Alois P. Heinz, <a href="/A008963/b008963.txt">Table of n, a(n) for n = 0..10000</a> (first 1001 terms from T. D. Noe)
%H A008963 William Webb, <a href="https://web.archive.org/web/2024*/https://www.fq.math.ca/Scanned/13-4/webb.pdf">Distribution of the first digits of Fibonacci numbers</a>, The Fibonacci Quarterly, Vol. 13, No. 4 (1975), pp. 334-336.
%H A008963 Wikipedia, <a href="http://en.wikipedia.org/wiki/Benford's_law">Benford's law</a>.
%H A008963 J. Wlodarski, <a href="https://web.archive.org/web/2024*/https://www.fq.math.ca/Scanned/9-1/wlodarski2.pdf">Fibonacci and Lucas Numbers Tend to Obey Benford's Law</a>, The Fibonacci Quarterly, Vol. 9, No. 1 (1971), pp. 87-88.
%H A008963 <a href="/index/Be#Benford">Index entries for sequences related to Benford's law</a>.
%F A008963 a(n) = A000030(A000045(n)). - _Amiram Eldar_, Sep 23 2019
%F A008963 Asymptotic mean: Limit_{m->oo} (1/m) * Sum_{k=1..m} a(k) = Sum_{d=1..9} d*log(1+1/d)/log(10) = 3.440236... (A213201). - _Amiram Eldar_, Jan 12 2023
%F A008963 For n>5, a(n) = floor(10^{alpha*n-beta}), where alpha=log_10(phi), beta=log_10(5)/2, {x}=x-floor(x) denotes the fractional part of x, log_10(phi) = A097348, and phi = (1+sqrt(5))/2 = A001622. - _Hans J. H. Tuenter_, Aug 20 2025
%p A008963 F:= combinat[fibonacci]:
%p A008963 a:= n-> parse(""||(F(n))[1]):
%p A008963 seq(a(n), n=0..100); # _Alois P. Heinz_, Nov 22 2023
%t A008963 Table[IntegerDigits[Fibonacci[n]][[1]], {n, 0, 100}] (* _T. D. Noe_, Sep 23 2011 *)
%o A008963 (PARI) vector(10001,n,f=fibonacci(n-1);f\10^(#Str(f)-1))
%o A008963 (Haskell)
%o A008963 a008963 = a000030 . a000045 -- _Reinhard Zumkeller_, Sep 09 2015
%Y A008963 Cf. A000045, A003893 (final digit).
%Y A008963 Cf. A000030, A261607, A213201.
%K A008963 nonn,base,easy,changed
%O A008963 0,4
%A A008963 _N. J. A. Sloane_