



1, 4, 9, 20, 32, 59, 88, 159, 231, 444, 659, 1262, 1897, 3814, 1187707
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OFFSET

1,2


COMMENTS

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).


LINKS

Table of n, a(n) for n=1..15.


FORMULA

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)}.


EXAMPLE

a(15) = 1 + 3 + 5 + 11 + 12 + 27 + 29 + 71 + 72 + 213 + 215 + 603 + 635 + 1917 + 1183893 is prime.


CROSSREFS

Cf. A000142, A014597, A025494, A051761, A059589.
Sequence in context: A297190 A075385 A048150 * A241944 A256054 A164931
Adjacent sequences: A177438 A177439 A177440 * A177442 A177443 A177444


KEYWORD

hard,nonn


AUTHOR

Jonathan Vos Post, May 08 2010


STATUS

approved



