A105388 - OEIS

A105388

Number of divisors of concatenated even numbers.

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

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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

Adjacent sequences: A105385 A105386 A105387 * A105389 A105390 A105391

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