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A039832
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Numbers n such that n and n+1 both have 4 divisors.
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5
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14, 21, 26, 33, 34, 38, 57, 85, 86, 93, 94, 118, 122, 133, 141, 142, 145, 158, 177, 201, 202, 205, 213, 214, 217, 218, 253, 298, 301, 302, 326, 334, 381, 393, 394, 445, 446, 453, 481, 501, 514, 526, 537, 542, 553, 565, 622, 633, 634, 694, 697, 698, 706, 717, 745, 766, 778, 793, 802, 817
(list; graph; refs; listen; history; internal format)
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OFFSET
| 1,1
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REFERENCES
| D. Wells, Curious and interesting numbers, Penguin Books.
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EXAMPLE
| 14 and 15 both have 4 as number of divisors and are consecutive.
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PROG
| (PARI) isA039832(n) = (numdiv(n)==4) && (numdiv(n+1)==4) [From Michael B. Porter (michael_b_porter(AT)yahoo.com), Feb 03 2010]
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CROSSREFS
| Cf. A038456, A039833.
Sequence in context: A025339 A096017 A006614 * A108633 A110478 A125967
Adjacent sequences: A039829 A039830 A039831 * A039833 A039834 A039835
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KEYWORD
| nonn
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AUTHOR
| N. J. A. Sloane (njas(AT)research.att.com), Felice Russo (frusso(AT)micron.com), Olivier Gerard (olivier.gerard(AT)gmail.com)
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