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!)
 A261213 Odd numbers n such that n^2 = m + (m+1), where both m and m+1 have no repeated digits. 1
 1, 3, 5, 7, 9, 11, 13, 23, 27, 29, 31, 35, 37, 39, 41, 43, 57, 63, 69, 77, 81, 87, 89, 95, 109, 113, 121, 125, 127, 129, 137, 163, 193, 219, 239, 271, 273, 279, 281, 285, 305, 311, 315, 331, 339, 353, 357, 377, 381, 395, 403, 409, 435, 441, 443, 597 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 COMMENTS This sequence is finite and a(146) = 40797 is the last term. 40797^2 = 1664395209 and 1664395209 = 832197604 + 832197605. These last two numbers both have no repeating digits. LINKS Pieter Post, Table of n, a(n) for n = 1..146 EXAMPLE 5 is in the sequence, because 5^2 = 25. 25 = 12 + 13. 12 and 13 both have no repeating digits. MATHEMATICA nr[n_] := 1 == Max@ DigitCount@ n; Select[ Range[1, 10^5, 2], nr[x= Floor[#^2 / 2]] && nr[x + 1] &] (* Giovanni Resta, Aug 12 2015 *) CROSSREFS Cf. A036745, A071519, A156977. Sequence in context: A030155 A143448 A226484 * A130738 A239036 A024323 Adjacent sequences:  A261210 A261211 A261212 * A261214 A261215 A261216 KEYWORD nonn,full,fini,base AUTHOR Pieter Post, Aug 12 2015 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 6 06:00 EDT 2021. Contains 343580 sequences. (Running on oeis4.)