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The terms of A055258 (sums of two powers of 7) divided by 2.
1

%I #3 Mar 30 2012 17:24:45

%S 1,4,7,25,28,49,172,175,196,343,1201,1204,1225,1372,2401,8404,8407,

%T 8428,8575,9604,16807,58825,58828,58849,58996,60025,67228,117649,

%U 411772,411775,411796,411943,412972,420175,470596,823543

%N The terms of A055258 (sums of two powers of 7) divided by 2.

%F (7^n + 7^m) / 2, n = 0, 1, 2, 3 ..., m = 0, 1, 2, 3, ... n.

%e a(4) = 25 = (7^2+7^0) / 2

%Y Cf. A055258.

%K easy,nonn

%O 1,2

%A _Jeremy Gardiner_, Jul 21 2002