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A071819 a(n) is the difference between the two smallest positive integers that you cannot obtain using the integers {1,2,...,n} at most once and the four operators +, -, *, /. 0
1, 1, 1, 2, 3, 23, 5, 144, 98, 658 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,4

LINKS

Table of n, a(n) for n=1..10.

G. Bannay, LE COMPTE EST BON

Index entries for similar sequences

EXAMPLE

a(4)=2 because 29 and 31 are the smallest numbers that you cannot obtain using {1,2,3,4} and the four operations and 31-29 = 2.

CROSSREFS

Cf. A060315.

Sequence in context: A114101 A114007 A282795 * A085946 A280894 A042585

Adjacent sequences:  A071816 A071817 A071818 * A071820 A071821 A071822

KEYWORD

hard,more,nonn

AUTHOR

Koksal Karakus (karakusk(AT)hotmail.com), Jun 07 2002

STATUS

approved

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Last modified October 14 03:00 EDT 2019. Contains 327995 sequences. (Running on oeis4.)