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

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A066133 In base 2, twelve 'Reverse and Add' steps are needed to reach a palindrome. 1
 1027, 1139, 1181, 1229, 1433, 1481, 1537, 1649, 1951, 1983, 1999, 2031, 2051, 3073, 3103, 3215, 3351, 3463, 3611, 3639, 3671, 3723, 3751, 3783, 3839, 3859, 3971, 4087, 4103, 4121, 4141, 4187, 4237, 4269, 4327, 4331, 4333, 4361, 4427, 4603, 4625, 4645 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS The analog of A065217 in base 2. The number of steps starts at 0, so palindromes (cf. A006995) are excluded. LINKS Harry J. Smith, Table of n, a(n) for n=1..1000 Index entries for sequences related to Reverse and Add! PROG (PARI) Rev(x)= { local(d, r=0); while (x>0, d=x%10; x\=10; r=r*10 + d); return(r) } digitsIn(x)= { local(d); if (x==0, return(1)); d=1 + log(x)\log(10); if (10^d == x, d++, if (10^(d-1) > x, d--)); return(d) } Palin(x)= { local(d, e, f, i, t, y); if (x==0, return(1)); y=x; d=digitsIn(x); t=10^(d - 1); for (i=1, d\2, f=y-10*(y\10); y\=10; e=x\t; x-=t*e; t/=10; if (e!=f, return(0)) ); return(1) } baseE(x, b)= { local(d, e=0, f=1); while (x>0, d=x-b*(x\b); x\=b; e+=d*f; f*=10); return(e) } baseI(x, b)= { local(d, e=0, f=1); while (x>0, d=x-10*(x\10); x\=10; e+=d*f; f*=b); return(e) } calcB(p)= { local(b, r); b=baseE(p, 2); r=Rev(b); d=baseI(r, 2) + p; b=baseE(d, 2); return(b); } { n=0; for (m=1, 10^9, d=m; t=1; b=baseE(d, 2); for (i=1, 12, if (Palin(b), t=0; break); b=calcB(d)); if (t && Palin(b), write("b066133.txt", n++, " ", m); if (n==1000, return)) ) } \\ Harry J. Smith, Feb 01 2010 CROSSREFS Cf. A006995, A065217, A066122. Sequence in context: A246245 A235692 A247947 * A119455 A252772 A168189 Adjacent sequences: A066130 A066131 A066132 * A066134 A066135 A066136 KEYWORD base,nonn AUTHOR Klaus Brockhaus, Dec 08 2001 EXTENSIONS OFFSET changed from 0,1 to 1,1 by Harry J. Smith, Feb 01 2010 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 September 16 22:04 EDT 2024. Contains 375979 sequences. (Running on oeis4.)