

A111034


Sum of squares of digits of e.


2



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
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OFFSET

1,1


COMMENTS

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.


LINKS

Table of n, a(n) for n=1..44.


FORMULA

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


EXAMPLE

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.


MATHEMATICA

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


CROSSREFS

Cf. A001113.
Sequence in context: A015001 A193914 A219160 * A214367 A241872 A109801
Adjacent sequences: A111031 A111032 A111033 * A111035 A111036 A111037


KEYWORD

base,easy,nonn


AUTHOR

Jonathan Vos Post, Oct 05 2005


EXTENSIONS

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


STATUS

approved



