A248171 Partition of the positive integers on minimal blocks such that concatenation of numbers in each block is an evil number (A001969). Sequence lists the evil numbers obtained in this way.

12, 3, 45, 6, 78, 9, 10, 1112, 1314, 15, 161718, 1920, 2122, 23, 24, 2526, 27, 2829, 30, 3132, 33, 34, 3536, 37383940, 414243, 4445464748, 495051, 52535455, 5657, 58, 5960, 6162, 63, 646566, 6768, 6970, 71, 72, 7374, 75, 7677787980, 818283, 8485868788, 89, 90

Offset

1,1

Comments

The numbers of the consecutive positive integers over blocks of the partition are 2,1,2,1,2,1,1,2,2,1,3,2,2,1,1,2,1,...

Links

Peter J. C. Moses, Table of n, a(n) for n = 1..1000

Prog

(Python)
from itertools import count
def evil(n): return bin(n)[2:].count('1') % 2 == 0
def aupton(terms):
    alst, t = [], 0
    for k in count(1):
        t = int(str(t) + str(k))
        if evil(t):
            alst.append(t)
            t = 0
            if len(alst) >= terms: return alst
print(aupton(45)) # Michael S. Branicky, Dec 03 2021

Crossrefs

Cf. A000069 (odious), A001969 (evil), A248009, A248138, A248140, A248172 (similar, with odious).

Sequence in context: A040139 A317312 A112033 * A258227 A130895 A367431

Adjacent sequences: A248168 A248169 A248170 * A248172 A248173 A248174

Keyword

nonn,base

Author

Vladimir Shevelev, Oct 03 2014

Extensions

More terms from Peter J. C. Moses, Oct 04 2014

Status

approved