%I #16 Nov 04 2013 12:19:17
%S 53,71,79,97,153,171,179,197,253,271,279,297,353,371,379,397,453,471,
%T 479,497,553,571,579,597,653,671,679,697,753,771,779,797,853,871,879,
%U 897,953,971,979,997,1053,1071,1079,1097,1153,1171,1179,1197,1253,1271
%N 7-ish numbers (end in 53, 71, 79, 97).
%H Reinhard Zumkeller, <a href="/A045807/b045807.txt">Table of n, a(n) for n = 1..1000</a>
%F Empirical G.f.: x*(53+18*x+8*x^2+18*x^3+3*x^4)/(1-x-x^4+x^5). [Colin Barker, Jan 23 2012]
%o (Haskell)
%o import Data.List (findIndices)
%o a045807 n = a045807_list !! (n-1)
%o a045807_list = findIndices (`elem` [53,71,79,97]) $ cycle [0..99]
%o -- _Reinhard Zumkeller_, Jan 23 2012
%Y Cf. A045800-A045809.
%Y Cf. A045572, A045797, A045798.
%K nonn,base,easy
%O 1,1
%A _J. H. Conway_.
%E More terms from _Erich Friedman_.