A114807 The numbers 4^n-1 written in groups of three digits, with leading zeros omitted.

315, 632, 551, 23, 409, 516, 383, 655, 352, 621, 431, 48, 575, 419, 430, 316, 777, 215, 671, 88, 632, 684, 354, 551, 73, 741, 823, 429, 496, 729, 517, 179, 869, 183, 687, 194, 767, 352, 748, 779, 69, 431, 99, 511, 627, 775, 439, 804, 651, 110, 317, 592, 186, 44

Offset

1,1

Links

Table of n, a(n) for n=1..54.

Example

3, 15, 63, 255, 1023, 4095, 16383, ...

Mathematica

FromDigits[#] & /@ Partition[ Flatten@ IntegerDigits@ Table[4^n - 1, {n, 22}], 3] (* Robert G. Wilson v, Jun 23 2014 *)

Prog

(Python)
from itertools import count, islice
def bgen(): yield from (d for n in count(1) for d in str((1 << 2*n)-1))
def agen(): g = bgen(); yield from (int("".join(t)) for t in zip(g, g, g))
print(list(islice(agen(), 54))) # Michael S. Branicky, Dec 25 2022

Crossrefs

Cf. A114645, A114804, A114808, A114827.

Sequence in context: A349868 A349937 A076773 * A109130 A284981 A341358

Adjacent sequences: A114804 A114805 A114806 * A114808 A114809 A114810

Keyword

base,dumb,nonn

Author

Jonathan Vos Post, Feb 19 2006

Extensions

a(4) and following changed by Georg Fischer, Dec 25 2022

Status

approved