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 A262715 #29 May 16 2025 19:02:00
%S A262715 29,24389,20511149,17249876309,14507145975869,12200509765705829,
%T A262715 10260628712958602189,8629188747598184440949,
%U A262715 7257147736730073114838109,6103261246589991489578849669,5132842708382182842735812571629,4316720717749415770740818372739989
%N A262715 a(n) = 29^(2*n+1).
%C A262715 29*a(n) is a square.
%H A262715 G. C. Greubel, <a href="/A262715/b262715.txt">Table of n, a(n) for n = 0..250</a>
%H A262715 <a href="/index/Rec#order_01">Index entries for linear recurrences with constant coefficients</a>, signature (841).
%F A262715 G.f.: 29/(1 - 841*x).
%F A262715 a(n) = 841*a(n-1).
%F A262715 Sum_{i>=0} (-1)^i/a(i) = 29*A021846; Sum_{i>=0} 1/a(i) = 2.9*A021088. [_Bruno Berselli_, Oct 06 2015]
%t A262715 29^Range[1, 30, 2]
%t A262715 NestList[841#&,29,20] (* _Harvey P. Dale_, May 16 2025 *)
%o A262715 (Magma) [29^(2*n+1): n in [0..15]];
%o A262715 (PARI) vector(20, n, n--; 29^(2*n+1)) \\ _Altug Alkan_, Oct 02 2015
%Y A262715 Second bisection of A009973 (powers of 29).
%Y A262715 Cf. similar sequences of the form p^(2*n+1), with p prime: A004171 (p=2), A013708 (p=3), A013710 (p=5), A013712 (p=7), A013716 (p=11), A013718 (p=13), A013722 (p=17), A013724 (p=19), A013728 (p=23), this sequence (p=29), A262716 (p=31), A262786 (p=37), A262787 (p=41), A155477 (p=43).
%K A262715 nonn,easy
%O A262715 0,1
%A A262715 _Vincenzo Librandi_, Oct 02 2015