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!)
 A226471 Numbers n such that n^2 XOR triangular(n) is a triangular number. XOR is the bitwise logical exclusive-or operator. 0
 0, 1, 3, 7, 15, 25, 31, 63, 113, 127, 189, 200, 255, 381, 481, 499, 511, 765, 1004, 1011, 1023, 1533, 1785, 1808, 1985, 2023, 2035, 2047, 3069, 3199, 3255, 3577, 3810, 4071, 4083, 4095, 4446, 6141, 6399, 7161, 8065, 8135, 8167, 8179, 8191, 12285, 12799, 14279, 14280 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,3 COMMENTS Indices of triangular numbers in A226470. Numbers n such that A226470(n) and A226470(n+1) are triangular numbers: 0, 14279, 491279, 16251935, 29358023, 528478271, ... LINKS PROG (Python) import math for n in range(100000000):   a = (n*n) ^ (n*(n+1)/2)   r = int(math.sqrt(a*2))   if r*(r+1)==a*2:  print n, CROSSREFS Cf. A000217, A000290, A226470, A224218. Sequence in context: A066460 A114221 A289828 * A175510 A144643 A034757 Adjacent sequences:  A226468 A226469 A226470 * A226472 A226473 A226474 KEYWORD nonn,base AUTHOR Alex Ratushnyak, Jun 08 2013 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 June 15 15:09 EDT 2021. Contains 345049 sequences. (Running on oeis4.)