The OEIS is supported by the many generous donors to the OEIS Foundation.

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A224242 Numbers k such that k^2 XOR (k+1)^2 is a square, and k^2 XOR (k-1)^2 is a square, where XOR is the bitwise logical XOR operator. 0
 0, 4, 24, 44, 112, 480, 1984, 8064, 32512, 130560, 263160, 278828, 340028, 523264, 2095104, 8384512, 25239472, 32490836, 33546240, 134201344, 536838144, 2147418112 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 COMMENTS A subsequence of A221643: k's such that A221643(k) = A221643(k-1) + 1. A059153 is a subsequence. Terms that are not in A059153: 0, 44, 263160, 278828, 340028, 25239472, 32490836. Conjecture: the subsequence of non-A059153 terms is infinite. LINKS PROG (C) #include #include int main() {   unsigned long long a, i, t;   for (i=0; i < (1L<<32)-1; ++i) {       a = (i*i) ^ ((i+1)*(i+1));       t = sqrt(a);       if (a != t*t) continue;       a = (i*i) ^ ((i-1)*(i-1));       t = sqrt(a);       if (a != t*t) continue;       printf("%llu, ", i);   }   return 0; } CROSSREFS Cf. A221643, A059153. Sequence in context: A031117 A174178 A139245 * A066770 A080380 A039935 Adjacent sequences:  A224239 A224240 A224241 * A224243 A224244 A224245 KEYWORD nonn,base,less AUTHOR Alex Ratushnyak, Apr 01 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 January 28 23:12 EST 2022. Contains 350670 sequences. (Running on oeis4.)