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 A073218 #8 Apr 08 2025 12:45:12 %S A073218 1,4,7,25,28,49,172,175,196,343,1201,1204,1225,1372,2401,8404,8407, %T A073218 8428,8575,9604,16807,58825,58828,58849,58996,60025,67228,117649, %U A073218 411772,411775,411796,411943,412972,420175,470596,823543 %N A073218 The terms of A055258 (sums of two powers of 7) divided by 2. %F A073218 T(n,m) = (7^n + 7^m) / 2, n = 0, 1, 2, 3 ..., m = 0, 1, 2, 3, ... n. %e A073218 T(2,0) = 25 = (7^2+7^0) / 2. %Y A073218 Cf. A055258. %K A073218 nonn,tabl,easy %O A073218 0,2 %A A073218 _Jeremy Gardiner_, Jul 21 2002 %E A073218 Offset changed by _Alois P. Heinz_, Apr 08 2025