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 A254067 #12 Nov 05 2015 14:31:10 %S A254067 1,8,4,5,17,7,68,32,26,10,41,149,59,35,13,608,284,230,86,44,16,365, %T A254067 1337,527,311,113,53,19,5468,2552,2066,770,392,140,62,22,3281,12029, %U A254067 4739,2795,1013,473,167,71,25,49208,22964,18590,6926,3524,1256,554,194,80,28 %N A254067 Rectangular array A read by upward antidiagonals in which the entry in row n and column k is defined by A(n,k) = S(4*A257499(n,k) - 3), n,k >= 1, where the function S is as defined in A257480. %C A254067 Theorem: For all indices n and k such that n + k > 2, log(A(n,k))/log(A257499(n,k)) < log_2(3). %C A254067 Conjecture: Arranging the sequence in ascending order gives A189707 (positions of 0 in A189706). %F A254067 A(n,k) = S(4*A257499(n,k) - 3) = (3 + 3^n*(6*k - 3 + 2*(-1)^n))/6, where the function S is as defined in A257480. %F A254067 For all k, A(1,k) <= A257499(1,k), and A(n,k) > A257499(n,k), for all n > 1. %e A254067 . 1 4 7 10 13 16 19 22 25 28 %e A254067 . 8 17 26 35 44 53 62 71 80 89 %e A254067 . 5 32 59 86 113 140 167 194 221 248 %e A254067 . 68 149 230 311 392 473 554 635 716 797 %e A254067 . 41 284 527 770 1013 1256 1499 1742 1985 2228 %e A254067 . 608 1337 2066 2795 3524 4253 4982 5711 6440 7169 %e A254067 . 365 2552 4739 6926 9113 11300 13487 15674 17861 20048 %e A254067 . 5468 12029 18590 25151 31712 38273 44834 51395 57956 64517 %e A254067 . 3281 22964 42647 62330 82013 101696 121379 141062 160745 180428 %e A254067 . 49208 108257 167306 226355 285404 344453 403502 462551 521600 580649 %t A254067 (* Array antidiagonals flattened: *) %t A254067 v[x_] := IntegerExponent[x, 2]; f[x_] := (3*x + 1)/2^v[3*x + 1]; s[x_] := (3 + (3/2)^v[1 + f[x]] (1 + f[x]))/6; A257499[n_, k_] := (1 + 2^n*(6*k - 3 + 2*(-1)^n))/3; A254067[n_, k_] := s[4*A257499[n, k] - 3]; Flatten[Table[A254067[n - k + 1, k], {n, 10}, {k, n}]] %K A254067 nonn,tabl %O A254067 1,2 %A A254067 _L. Edson Jeffery_, May 02 2015