The OEIS mourns the passing of Jim Simons and is grateful to the Simons Foundation for its support of research in many branches of science, including the OEIS.
The OEIS is supported by the many generous donors to the OEIS Foundation.

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A104023 Numbers that have more than one way of being written as k^2*j with 0 < j <= k and gcd(k, j) = 1. 4
 100, 196, 324, 484, 676, 900, 1089, 1156, 1444, 1521, 1764, 2028, 2116, 2304, 2500, 2601, 2916, 3249, 3364, 3468, 3600, 3844, 4332, 4356, 4624, 4761, 4900, 5476, 5625, 5776, 6084, 6348, 6498, 6724, 7056, 7396, 7500, 7569, 8100, 8464, 8649, 8820, 8836 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 LINKS Table of n, a(n) for n=1..43. MATHEMATICA t = Sort[ Flatten[ Table[ If[ GCD[k, j] == 1, k^2*j, {}], {k, 1000}, {j, k}]]]; u = Table[ Count[t, n], {n, 9215}]; Select[ Range[9215], u[[ # ]] > 1 &] CROSSREFS Cf. A104022, A102448, A104021. Sequence in context: A369417 A231088 A365745 * A072367 A172178 A036742 Adjacent sequences: A104020 A104021 A104022 * A104024 A104025 A104026 KEYWORD nonn AUTHOR Leroy Quet and Robert G. Wilson v, Feb 24 2005 STATUS approved

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

Last modified June 13 03:56 EDT 2024. Contains 373366 sequences. (Running on oeis4.)