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Search: id:A111034
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| A111034 |
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Sum of squares of digits of e. |
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+0
3
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| 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
(list; graph; listen)
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OFFSET
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1,1
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COMMENT
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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.
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FORMULA
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a(n) = sum(i=1 to n) A001113(i)^2.
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EXAMPLE
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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.
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CROSSREFS
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Cf. A001113.
Sequence in context: A055974 A009671 A015001 this_sequence A109801 A099340 A158259
Adjacent sequences: A111031 A111032 A111033 this_sequence A111035 A111036 A111037
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KEYWORD
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base,easy,nonn
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AUTHOR
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Jonathan Vos Post (jvospost3(AT)gmail.com), Oct 05 2005
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