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1, 4, 9, 20, 32, 59, 88, 159, 231, 444, 659, 1262, 1897, 3814, 1187707
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OFFSET
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1,2
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COMMENTS
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Partial sums of numbers n such that n^2 is a sum of distinct factorials. The subsequence of primes in this partial sum begins: 59, 659, 1187707. If there is a larger value (the sequence might be finite), a(n)^2 must be greater than 48! (about 1.24139 * 10^61).
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LINKS
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FORMULA
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a(n) = SUM[i=1..n] A014597(i) = SUM[i=1..n] {i such that i^2 is a sum of distinct factorials} = SUM[i=1..n] {i such that i^2 is a sum of distinct A000142(j)}.
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EXAMPLE
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a(15) = 1 + 3 + 5 + 11 + 12 + 27 + 29 + 71 + 72 + 213 + 215 + 603 + 635 + 1917 + 1183893 is prime.
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CROSSREFS
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KEYWORD
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hard,nonn
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AUTHOR
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STATUS
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approved
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