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A036433 Number of divisors is a digit in the base 10 representation of n. 2
1, 2, 14, 23, 29, 34, 46, 63, 68, 74, 76, 78, 88, 94, 116, 127, 128, 134, 138, 141, 142, 143, 145, 146, 164, 182, 184, 186, 189, 194, 196, 211, 214, 223, 227, 229, 233, 236, 238, 239, 241, 247, 248, 249, 251, 254, 257, 258, 261, 263, 268, 269, 271, 274, 277 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

Invented by the HR concept formation program.

LINKS

Reinhard Zumkeller, Table of n, a(n) for n = 1..10000

S. Colton, Refactorable Numbers - A Machine Invention, J. Integer Sequences, Vol. 2, 1999, #2.

S. Colton, HR - Automatic Theory Formation in Pure Mathematics

EXAMPLE

14 has 4 divisors and 4 is a digit in the base 10 representation of 14.

MATHEMATICA

Select[Range[300], MemberQ[IntegerDigits[#], DivisorSigma[0, #]]&] (* Harvey P. Dale, Sep 02 2013 *)

PROG

(Haskell)

a036433 n = a036433_list !! (n-1)

a036433_list = filter f [1..] where

   f x = d < 10 && ("0123456789" !! d) `elem` show x where d = a000005 x

-- Reinhard Zumkeller, Mar 15 2012

(Python)

from sympy import divisor_count

A036433_list = []

for i in range(1, 10**5):

....d = divisor_count(i)

....if d < 10 and str(d) in str(i):

........A036433_list.append(i) # Chai Wah Wu, Jan 07 2015

CROSSREFS

Cf. A045708, A208272.

Cf. A000005.

Sequence in context: A069512 A116639 A220274 * A172048 A226334 A109255

Adjacent sequences:  A036430 A036431 A036432 * A036434 A036435 A036436

KEYWORD

base,nice,nonn

AUTHOR

Simon Colton (simonco(AT)cs.york.ac.uk)

STATUS

approved

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Last modified May 22 05:03 EDT 2019. Contains 323473 sequences. (Running on oeis4.)