A028948 An "extremely strange sequence": a(n+1) = [ A*a(n)+B ]/p^r, where p^r is the highest power of p dividing [ A*a(n)+B ] and p=2, A=4.001, B=1.2.

0, 1, 5, 21, 85, 341, 1365, 2731, 10927, 5465, 10933, 1367, 2735, 10943, 5473, 10949, 1369, 2739, 10959, 5481, 10965, 1371, 2743, 10975, 5489, 10981, 1373, 2747, 10991, 5497, 10997, 1375, 2751, 11007, 5505, 11013, 1377, 2755, 11023, 5513, 11029, 1379, 2759

Offset

0,3

Links

Alois P. Heinz, Table of n, a(n) for n = 0..3740

Formula

a(n+1) = A000265(floor(A*a(n)+B)). - M. F. Hasler, Aug 07 2018

Prog

(PARI) vector(50, i, if(i>1, t=(t*4001+1200)\1000; t>>=valuation(t, 2), t=0)) \\ M. F. Hasler, Aug 07 2018
(Python)
from itertools import islice
def A028948_gen(): # generator of terms
    x = 0
    while True:
        yield x
        x = (y:=(x*4001+1200)//1000)>>(~y&y-1).bit_length()
A028948_list = list(islice(A028948_gen(), 30)) # Chai Wah Wu, Dec 28 2023

Crossrefs

Cf. A000265.

Sequence in context: A247001 A271157 A255451 * A084241 A002450 A187063

Adjacent sequences: A028945 A028946 A028947 * A028949 A028950 A028951

Keyword

nonn,easy

Author

Yasutoshi Kohmoto

Extensions

a(0)=0 inserted by M. F. Hasler, Aug 07 2018

Status

approved