login
A105388
Number of divisors of concatenated even numbers.
2
2, 8, 8, 6, 32, 12, 4, 48, 96, 48, 8, 40, 64, 24, 32, 32, 12, 96, 16, 448, 64, 48, 256, 16, 192, 36, 24, 640, 32, 192, 16, 32, 256, 72, 256, 288, 16, 384, 256, 256, 32, 12, 128, 60, 160, 1536, 2048, 64, 16, 2304, 64, 64, 96, 72, 32, 48, 512, 24, 256, 1536, 64, 72, 768, 40, 4096, 48, 16, 512, 1024, 48, 1024
OFFSET
1,1
LINKS
Max Alekseyev, Table of n, a(n) for n = 1..90 (terms 88..89 from Tyler Busby).
EXAMPLE
The number of divisors of 24 is 8 - which is the second term.
The number of divisors of 246 is 8 - which is the third term.
The number of divisors of 2468 is 6 - which is the fourth term.
MATHEMATICA
Table[DivisorSigma[0, FromDigits[Flatten[IntegerDigits/@(2Range[n])]]], {n, 30}] (* Harvey P. Dale, Dec 10 2016 *)
CROSSREFS
Cf. A019520, A108728 (number of distinct prime divisors).
Sequence in context: A198367 A021780 A020769 * A178247 A048651 A243596
KEYWORD
base,nonn
AUTHOR
Parthasarathy Nambi, Apr 30 2005
EXTENSIONS
More terms from Harvey P. Dale, Dec 10 2016
a(30)-a(69) from Michael S. Branicky, Feb 08 2021 (computed using prime factorizations linked in A108728)
Offset corrected and a(70)-a(71) added by Max Alekseyev, Mar 21 2023
STATUS
approved