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 A113829 #22 Jan 02 2022 00:32:21 %S A113829 1,9,25,57,185,441,4537,37305,102841,233913,758201,1806777,18583993, %T A113829 152801721,421237177,958108089,3105591737,7400559033,76120035769, %U A113829 625875849657,1725387477433,3924410732985,12720503755193,30312689799609 %N A113829 a(n) = a(n-1) + 2^(k(n)), where k(n) is the n-th term of the sequence of numbers that are congruent to {0,3,4,5,7,8} mod 12. %H A113829 <a href="/index/Rec#order_07">Index entries for linear recurrences with constant coefficients</a>, signature (1,0,0,0,0,4096,-4096). %F A113829 G.f.: (9+16*x+32*x^2+128*x^3+256*x^4+4096*x^5-4096*x^6)/(1-x-4096*x^6+4096*x^7). - _Charles R Greathouse IV_, Apr 05 2012 %t A113829 LinearRecurrence[{1,0,0,0,0,4096,-4096},{1,9,25,57,185,441,4537},30] (* _Harvey P. Dale_, Aug 04 2018 *) %o A113829 (PARI) Vec((-4096*x^6+4096*x^5+256*x^4+128*x^3+32*x^2+16*x+9)/(4096*x^7 - 4096*x^6-x+1)+O(x^99)) \\ _Charles R Greathouse IV_, Apr 05 2012 %Y A113829 Cf. A099974, A112627, A080355, A080567, A099969, A099970, A099971, A154571. %K A113829 nonn,easy %O A113829 1,2 %A A113829 _Artur Jasinski_, Jan 27 2006 %E A113829 Better definition, corrected offset and edited by _Omar E. Pol_, Jan 08 2009