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%I #7 Nov 21 2013 12:48:44
%S 4,53,54,118,122,186,187,251,255,319,335,360,441,441,457,482,486,495,
%T 520,529,565,565,569,633,682,698,747,748,757,782,786,822,858,862,878,
%U 959,1008,1057,1082,1131,1135,1151,1200,1200
%N Sum of squares of digits of e.
%C a(n) is prime for n = 2, 8, 15, 23, 29, ... a(n) is semiprime for n = 1, 4, 5, 7, 10, 11, 16, 21, 22, 24, 26, ... a(n) is a perfect power for n = 1, 13, 14, 20, ... Coincidentally, a(20) = 529 = 23^2 = sum of squares of first 18 digits of pi.
%F a(n) = sum(i=1 to n) A001113(i)^2.
%e a(1) = 2^2 = 4,
%e a(2) = 2^2 + 7^2 = 53, which is prime,
%e a(3) = 2^2 + 7^2 + 1^2 = 54,
%e a(4) = 2^2 + 7^2 + 1^2 + 8^2 = 118,
%e a(5) = 2^2 + 7^2 + 1^2 + 8^2 + 2^2 = 122.
%t Accumulate[RealDigits[E,10,50][[1]]^2] (* _Harvey P. Dale_, Apr 05 2011 *)
%Y Cf. A001113.
%K base,easy,nonn
%O 1,1
%A _Jonathan Vos Post_, Oct 05 2005
%E More terms from Harvey P. Dale, Apr 05 2011.
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