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A091131 - OEIS
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A091131
Decimal expansion of e - 1.
10
1, 7, 1, 8, 2, 8, 1, 8, 2, 8, 4, 5, 9, 0, 4, 5, 2, 3, 5, 3, 6, 0, 2, 8, 7, 4, 7, 1, 3, 5, 2, 6, 6, 2, 4, 9, 7, 7, 5, 7, 2, 4, 7, 0, 9, 3, 6, 9, 9, 9, 5, 9, 5, 7, 4, 9, 6, 6, 9, 6, 7, 6, 2, 7, 7, 2, 4, 0, 7, 6, 6, 3, 0, 3, 5, 3, 5, 4, 7, 5, 9, 4, 5, 7, 1, 3, 8, 2, 1, 7, 8, 5, 2, 5, 1, 6, 6, 4, 2, 7, 4, 2
OFFSET
1,2
COMMENTS
Average length of the first increasing run in a random permutation of n integers as n->Infinity.
Engel expansion of number e - 1 is sequence of natural numbers (A000027). - Jaroslav Krizek, Jan 23 2014
FORMULA
Sum_{k >= 1} 1/k!. - Eric Desbiaux, Mar 21 2009
Equals Sum_{k>=1} H(k)*(k-1)/k!, where H(k) = A001008(k)/A002805(k) is the k-th harmonic number. - Amiram Eldar, Aug 19 2020
EXAMPLE
e - 1 = 1.71828182...
MATHEMATICA
RealDigits[N[E - 1, 105]][[1]]
PROG
(PARI) exp(1) - 1 \\ Michel Marcus, Aug 07 2019
CROSSREFS
KEYWORD
nonn,cons,easy
AUTHOR
Eric W. Weisstein, Dec 19 2003
STATUS
approved