A247346 Odd numbers n containing 1024 as the highest power of 2 in their Collatz (3x+1) iteration.

151, 201, 227, 341, 403, 423, 537, 605, 635, 715, 805, 847, 891, 909, 953, 955, 1003, 1073, 1075, 1129, 1131, 1191, 1271, 1273, 1337, 1431, 1433, 1505, 1613, 1693, 1697, 1783, 1787, 1907, 1911, 2007, 2011, 2147, 2149, 2257, 2259, 2263, 2377, 2383, 2421, 2503, 2541, 2547, 2675, 2681

Offset

1,1

Comments

a(n)*2^k also contains 1024 as the highest of 2 for any k >= 0.

Links

Derek Orr, Table of n, a(n) for n = 1..50

Prog

(PARI)
Max2(n)=v=[n]; while(n!=1, if(n==Mod(0, 2), n=n/2; v=concat(v, n)); if(n==Mod(1, 2)&&n!=1, n=3*n+1; v=concat(v, n))); k=1; while(vecsearch(vecsort(v), 2^k), k++); 2^(k-1)
n=1; while(n<10^4, if(n%2&&Max2(n)==1024, print1(n, ", ")); n++)

Crossrefs

Cf. A008908, A010120.

Sequence in context: A020359 A185936 A050969 * A300394 A142225 A334769

Adjacent sequences: A247343 A247344 A247345 * A247347 A247348 A247349

Keyword

nonn

Author

Derek Orr, Sep 22 2014

Status

approved