The OEIS Foundation is supported by donations from users of the OEIS and by a grant from the Simons Foundation.

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A133743 a(n) is the smallest positive square such that pairwise sums of distinct elements are all distinct. 4
 1, 4, 9, 16, 25, 36, 49, 100, 144, 169, 225, 256, 361, 441, 484, 625, 729, 784, 1156, 1521, 1600, 1764, 2401, 2704, 3364, 4096, 4225, 4356, 4900, 5184, 5929, 6889, 7921, 8836, 9216, 9409, 10404, 11881, 13689, 13924, 14161, 18496, 19321, 20449, 21316 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 LINKS Klaus Brockhaus, Table of n, a(n) for n = 1..4948 Eric Weisstein's World of Mathematics, B2-Sequence EXAMPLE 49 is in the sequence since the pairwise sums of distinct elements of {1, 4, 9, 16, 25, 36, 49} are all distinct: 5, 10, 13, 17, 20, 25, 26, 29, 34, 37, 40, 41, 45, 50, 52, 53, 58, 61, 65, 74, 85. 64 is not in the sequence since 1 + 64 = 16 + 49. CROSSREFS Cf. A000290, A062295, A133744, A133745. Sequence in context: A030288 A030154 A122541 * A235484 A028820 A122683 Adjacent sequences:  A133740 A133741 A133742 * A133744 A133745 A133746 KEYWORD nonn AUTHOR Klaus Brockhaus, Sep 24 2007 STATUS approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

Last modified May 7 12:56 EDT 2021. Contains 343650 sequences. (Running on oeis4.)