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A183530 An Ulam-type sequence: a(n) = n if n<=7; for n>7, a(n) = least number > a(n-1) which is a unique sum of 7 distinct earlier terms. 2
1, 2, 3, 4, 5, 6, 7, 28, 49, 50, 51, 52, 53, 54, 55, 70, 82, 91, 109, 112, 555, 556, 563, 564, 572, 573, 576, 583, 584, 591, 593, 1103, 1104, 1105, 1111, 1112, 1124, 1632, 1637, 1642, 1643, 1648, 1653, 1654, 1655, 1656, 1657, 1660, 1661, 1662, 1671, 1672, 2184 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

An Ulam-type sequence - see A002858 for further information.

LINKS

Alois P. Heinz, Table of n, a(n) for n = 1..500

Index entries for Ulam numbers

EXAMPLE

a(8) = 28 = 1 + ... + 7 = 7*8/2, because it is the least number >7 with a unique sum of 7 distinct earlier terms.

a(9) = 49 = 1 + ... + 6 + 28 = 7^2, because it is the least number >28 with a unique sum of 7 distinct earlier terms.

MAPLE

# see A183534 for programs.

CROSSREFS

Column k=7 of A183534.

Cf. A002858, A007086, A183527-A183533, A135737.

Sequence in context: A153687 A142594 A010351 * A173576 A024645 A004847

Adjacent sequences:  A183527 A183528 A183529 * A183531 A183532 A183533

KEYWORD

nonn

AUTHOR

Jonathan Vos Post and Alois P. Heinz, Jan 05 2011

STATUS

approved

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Last modified May 21 19:10 EDT 2019. Contains 323444 sequences. (Running on oeis4.)