A169855 EKG sequence started at 12 instead of 2.

12, 2, 4, 6, 3, 9, 15, 5, 10, 8, 14, 7, 21, 18, 16, 20, 22, 11, 33, 24, 26, 13, 39, 27, 30, 25, 35, 28, 32, 34, 17, 51, 36, 38, 19, 57, 42, 40, 44, 46, 23, 69, 45, 48, 50, 52, 54, 56, 49, 63, 60, 55, 65, 70, 58, 29, 87, 66, 62, 31, 93, 72, 64, 68, 74, 37, 111, 75, 78, 76, 80, 82, 41

Offset

1,1

Comments

A generalization of A064413.

Links

Peter Kagey, Table of n, a(n) for n = 1..10000

Prog

(Python)
from math import gcd
def aupton(terms):
    alst, aset = [12], {12}
    for n in range(2, terms+1):
        k = 2
        while True:
            while k in aset: k += 1
            if gcd(alst[-1], k) != 1:
                alst.append(k); aset.add(k); break
            k += 1
    return alst
print(aupton(73)) # Michael S. Branicky, Dec 02 2021

Crossrefs

For other initial terms, see A064413, A169837, A169839, A169841, A169843,A169845, A169847, A169849, A169851, A169853.

Sequence in context: A080496 A098781 A040142 * A054383 A036383 A107832

Adjacent sequences: A169852 A169853 A169854 * A169856 A169857 A169858

Keyword

nonn

Author

T. D. Noe and N. J. A. Sloane, Jun 02 2010

Status

approved