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 A062510 #39 Sep 08 2022 08:45:03 %S A062510 0,3,3,9,15,33,63,129,255,513,1023,2049,4095,8193,16383,32769,65535, %T A062510 131073,262143,524289,1048575,2097153,4194303,8388609,16777215, %U A062510 33554433,67108863,134217729,268435455,536870913,1073741823,2147483649 %N A062510 a(n) = 2^n + (-1)^(n+1). %C A062510 The identity 2 = 2^2/3 + 2^3/(3*3) - 2^4/(3*3*9) - 2^5/(3*3*9*15) + + - - can be viewed as a generalized Engel-type expansion of the number 2 to the base 2. Compare with A014551. - _Peter Bala_, Nov 13 2013 %D A062510 D. M. Burton, Elementary Number Theory, Allyn and Bacon, Inc. Boston, MA, 1976, p. 29. %H A062510 Vincenzo Librandi, <a href="/A062510/b062510.txt">Table of n, a(n) for n = 0..1000</a> %H A062510 G. Everest, Y. Puri and T. Ward, <a href="https://arxiv.org/abs/math/0204173">Integer sequences counting periodic points</a>, arXiv:math/0204173 [math.NT], 2002. %H A062510 <a href="/index/Rec#order_02">Index entries for linear recurrences with constant coefficients</a>, signature (1,2). %F A062510 a(n) = 3*A001045(n). - _Paul Curtz_, Jan 17 2008 %F A062510 G.f.: 3*x / ( (1+x)*(1-2*x) ) %F A062510 G.f.: Q(0) where Q(k)= 1 - 1/(4^k - 2*x*16^k/(2*x*4^k - 1/(1 + 1/(2*4^k - 8*x*16^k/(4*x*4^k + 1/Q(k+1) ))))); (continued fraction). - _Sergei N. Gladkovskii_, Apr 13 2013 %F A062510 E.g.f.: (exp(3*x) - 1)*exp(-x). - _Ilya Gutkovskiy_, Nov 20 2016 %t A062510 LinearRecurrence[{1,2},{0,3}, 30] (* or *) Table[2^n - (-1)^n, {n,0,30}] (* _G. C. Greubel_, Jan 15 2018 *) %o A062510 (PARI) for(n=0,22,print(2^n+(-1)^(n+1))) %o A062510 (Magma) [2^n + (-1)^(n+1): n in [0..40]]; // _Vincenzo Librandi_, Aug 14 2011 %Y A062510 Cf. A102345, A105723. %K A062510 easy,nonn %O A062510 0,2 %A A062510 _Jason Earls_, Jun 24 2001 %E A062510 More terms from Larry Reeves (larryr(AT)acm.org), Jul 06 2001