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A036438 Integers which can be written as m*tau(m) for some m, where tau = A000005. 2
1, 4, 6, 10, 12, 14, 22, 24, 26, 27, 32, 34, 38, 40, 46, 56, 58, 60, 62, 72, 74, 75, 80, 82, 84, 86, 88, 94, 104, 106, 108, 118, 120, 122, 132, 134, 136, 140, 142, 146, 147, 152, 156, 158, 166, 168, 178, 184, 192, 194, 202, 204, 206, 214, 218, 220, 226, 228, 232 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

Invented by the HR concept formation program.

LINKS

Table of n, a(n) for n=1..59.

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

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

EXAMPLE

10 = 5 * tau(5).

PROG

(PARI) isok(n) = {for (k=1, n, if (k*numdiv(k) == n, return (1)); ); return (0); } \\ Michel Marcus, Dec 09 2014

CROSSREFS

Cf. A000005, A001747, A036434.

Sequence in context: A114331 A102070 A026402 * A066190 A058012 A026411

Adjacent sequences:  A036435 A036436 A036437 * A036439 A036440 A036441

KEYWORD

easy,nonn

AUTHOR

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

STATUS

approved

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Last modified May 23 03:10 EDT 2019. Contains 323507 sequences. (Running on oeis4.)