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A137179 a(n) = the smallest positive integer m such that d(m) + d(m+1) = n, where d(m) is the number of positive divisors of m. (a(n) is the smallest m where A092405(m) = n.) 0
1, 2, 3, 5, 8, 11, 15, 20, 24, 39, 35, 59, 80, 84, 195, 167, 120, 119, 224, 239, 399, 335, 440, 359, 360, 480, 1520, 539, 899, 719, 1224, 720, 840, 1079, 3135, 1259, 5183, 1260, 2400, 2160, 1680, 1679, 9408, 2880, 7056, 2639, 3024, 2520, 6240, 2519, 7055, 6929 (list; graph; refs; listen; history; text; internal format)
OFFSET

3,2

LINKS

Table of n, a(n) for n=3..54.

MATHEMATICA

a = {}; For[n = 3, n < 60, n++, i = 1; While[ ! DivisorSigma[0, i] + DivisorSigma[0, i + 1] == n, i++ ]; AppendTo[a, i]]; a (* Stefan Steinerberger, May 18 2008 *)

CROSSREFS

Cf. A092405.

Sequence in context: A131073 A062485 A175143 * A096777 A125811 A281706

Adjacent sequences:  A137176 A137177 A137178 * A137180 A137181 A137182

KEYWORD

nonn

AUTHOR

Leroy Quet, May 11 2008

EXTENSIONS

More terms from Stefan Steinerberger, May 18 2008

STATUS

approved

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Last modified April 18 22:08 EDT 2019. Contains 322237 sequences. (Running on oeis4.)