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 A254312 #23 Nov 14 2015 01:57:55
%S A254312 3,32,7,170,64,11,1022,426,96,15,2726,2046,682,128,19,65526,10918,
%T A254312 3070,938,160,23,174742,131062,19110,4094,1194,192,27,2097110,436886,
%U A254312 196598,27302,5118,1450,224,31,11184726,4194262,699030,262134,35494,6142,1706,256,35
%N A254312 Rectangular array A read by upward antidiagonals in which the entry in row n and column k is defined by A(n,k) = (2^a(n)*(6*k - (3 - (-1)^a(n))*(1 - (-1)^n)/2) - 2^n + 4)/6, n,k >= 1, where {a(n)} is the Beatty sequence A117630 defined by a(n) = floor(n*log(3)/log(3/2)).
%C A254312 Conjecture: The array A contains without duplication all natural numbers m such that m < S(m), where the function S is as defined in A257480; i.e., the sequence is a permutation of A254311.
%e A254312 Array A begins:
%e A254312 . 3 7 11 15 19 23 27 31
%e A254312 . 32 64 96 128 160 192 224 256
%e A254312 . 170 426 682 938 1194 1450 1706 1962
%e A254312 . 1022 2046 3070 4094 5118 6142 7166 8190
%e A254312 . 2726 10918 19110 27302 35494 43686 51878 60070
%e A254312 . 65526 131062 196598 262134 327670 393206 458742 524278
%e A254312 . 174742 436886 699030 961174 1223318 1485462 1747606 2009750
%e A254312 . 2097110 4194262 6291414 8388566 10485718 12582870 14680022 16777174
%t A254312 (* Array antidiagonals flattened: *)
%t A254312 a[n_] := Floor[n*Log[3/2, 3]]; A254312[n_, k_] := (2^a[n]*(6*k - (3 - (-1)^a[n])*(1 - (-1)^n)/2) - 2^n + 4)/6; Flatten[Table[A254312[n - k + 1, k], {n, 9}, {k, n}]]
%Y A254312 Cf. A117630, A254311, A257480.
%Y A254312 Cf. A004767, A174312 (rows 1 and 2).
%K A254312 nonn,tabl
%O A254312 1,1
%A A254312 _L. Edson Jeffery_, May 03 2015