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 A353957 #18 Nov 10 2023 18:31:30 %S A353957 113,453,1813,7253,29013,116053,464213,1856853,7427413,29709653, %T A353957 118838613,475354453,1901417813,7605671253,30422685013,121690740053, %U A353957 486762960213,1947051840853,7788207363413,31152829453653,124611317814613,498445271258453,1993781085033813 %N A353957 a(n) = (85*4^n - 1)/3. %C A353957 When any term in the sequence is iterated using the Collatz function, its trajectory's only odd number before reaching 1 will be 85. %C A353957 Also, each term would have 2n+10 steps as its stopping time (A006577). %H A353957 <a href="/index/Rec#order_02">Index entries for linear recurrences with constant coefficients</a>, signature (5,-4). %e A353957 When n=5, a(5) = 29013 and when iterated using the Collatz function will have the following trajectory: 87040,43520,21760,10880,5440,2720,1360,680,340,170,85,256,128,64,32,16,8,4,2,1 %t A353957 (85*4^Range[25] - 1)/3 (* _Wesley Ivan Hurt_, Nov 10 2023 *) %o A353957 (PARI) a(n) = 85*4^n\3 \\ _Charles R Greathouse IV_, Sep 09 2022 %Y A353957 Subsequence of A198584. %Y A353957 Cf. A006577. %K A353957 nonn,easy %O A353957 1,1 %A A353957 _Krishna Kumar Arumugam_, Sep 03 2022 %E A353957 Simpler definition and more terms from _Jon E. Schoenfield_, Sep 09 2022