Accumulate[RealDigits[E, 10, 50][[1]]^2] (* From _Harvey P. Dale, _, Apr 05 2011 *)

_Jonathan Vos Post (jvospost3(AT)gmail.com), _, Oct 05 2005

proposed

approved

4, 53, 54, 118, 122, 186, 187, 251, 255, 319, 335, 360, 441, 441, 457, 482, 486, 495, 520, 529, 565, 565, 569, 633, 682, 698, 747, 748, 757, 782, 786, 822, 858, 862, 878, 959, 1008, 1057, 1082, 1131, 1135, 1151, 1200, 1200

Accumulate[RealDigits[E, 10, 50][[1]]^2] (* From Harvey P. Dale, Apr 05 2011 *)

More terms from Harvey P. Dale, Apr 05 2011.

approved

proposed

base,easy,nonn,new

Jonathan Vos Post (jvospost2jvospost3(AT)yahoogmail.com), Oct 05 2005

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 1st first 18 digits of pi.

base,easy,nonn,new

Sum of squares of digits of e.

4, 53, 54, 118, 122, 186, 187, 251, 255, 319, 335, 360, 441, 441, 457, 482, 486, 495, 520, 529, 565, 565, 569, 633, 682, 698, 747, 748, 757, 782

1,1

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 1st 18 digits of pi.

a(n) = sum(i=1 to n) A001113(i)^2.

a(1) = 2^2 = 4,

a(2) = 2^2 + 7^2 = 53, which is prime,

a(3) = 2^2 + 7^2 + 1^2 = 54,

a(4) = 2^2 + 7^2 + 1^2 + 8^2 = 118,

a(5) = 2^2 + 7^2 + 1^2 + 8^2 + 2^2 = 122.

Cf. A001113.

base,easy,nonn

Jonathan Vos Post (jvospost2(AT)yahoo.com), Oct 05 2005

approved