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A125309 Numbers n such that twice the sum of the prime factors of n equals the product of the digits of n. 0
4, 25, 76, 125, 187, 255, 437, 629, 1152, 1276, 1298, 1352, 1617, 1668, 2337, 3363, 3618, 4116, 4439, 5891, 6432, 8279, 11178, 13125, 14144, 14812, 14824, 18647, 22165, 22466, 23472, 24727, 24743, 25631, 26128, 32978, 37329, 42983, 48442 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Number of terms less than 10^n: 1, 3, 8, 22, 48, 103, 230, 611, ...; number of odd terms less than 10^n: 0, 1, 6, 12, 21, 51, 120, 331, ..., . - Robert G. Wilson v, Dec 12 2006

LINKS

Table of n, a(n) for n=1..39.

EXAMPLE

Prime factors of 76 are 2 and 19; twice their sum is 42 which the product of 7 and 6 - the digits of 76.

MATHEMATICA

Select[Range[2, 20000], Times @@ IntegerDigits[ # ] == 2 Plus @@ Transpose[FactorInteger[ # ]][[1]] &]

CROSSREFS

Similar to A067173 = numbers n such that the sum of the prime factors of n equals the product of the digits of n.

Sequence in context: A281339 A077205 A180569 * A273361 A266126 A041991

Adjacent sequences:  A125306 A125307 A125308 * A125310 A125311 A125312

KEYWORD

base,nonn

AUTHOR

Tanya Khovanova, Dec 10 2006

EXTENSIONS

More terms from Robert G. Wilson v, Dec 12 2006

STATUS

approved

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Last modified March 29 13:07 EDT 2017. Contains 284270 sequences.