A038489 Sums of 4 distinct powers of 9.

820, 6652, 7300, 7372, 7380, 59140, 59788, 59860, 59868, 65620, 65692, 65700, 66340, 66348, 66420, 531532, 532180, 532252, 532260, 538012, 538084, 538092, 538732, 538740, 538812, 590500, 590572, 590580, 591220, 591228, 591300, 597052, 597060, 597132, 597780, 4783060

Offset

1,1

Links

Amiram Eldar, Table of n, a(n) for n = 1..10000

Mathematica

Sort[Plus @@@ Subsets[9^Range[0, 6], {4}]] (* Amiram Eldar, Jul 14 2022 *)

Prog

(Python)
from itertools import islice
def A038489_gen(): # generator of terms
    yield int(bin(n:=15)[2:], 9)
    while True: yield int(bin((n:=n^((a:=-n&n+1)|(a>>1)) if n&1 else ((n&~(b:=n+(a:=n&-n)))>>a.bit_length())^b))[2:], 9)
A038489_list = list(islice(A038489_gen(), 30)) # Chai Wah Wu, Apr 05 2025

Crossrefs

Base-9 interpretation of A038446.

Cf. A001019, A038487, A038488.

Sequence in context: A037999 A248996 A043460 * A210150 A230784 A022254

Adjacent sequences: A038486 A038487 A038488 * A038490 A038491 A038492

Keyword

nonn,easy

Author

Olivier Gérard

Extensions

Offset corrected by Amiram Eldar, Jul 14 2022

Status

approved