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A115906 Numbers n such that n+sigma(n)+phi(n) is a triangular number. 0
1, 2, 5, 7, 9, 16, 144, 186, 410, 656, 680, 805, 963, 968, 1152, 1331, 1419, 1476, 1557, 1608, 2158, 2220, 2376, 2401, 2529, 2840, 3376, 3447, 3570, 3591, 4018, 5030, 5769, 5967, 6530, 6720, 6854, 6955, 7250, 7856, 8004, 8514, 8946, 9144 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

LINKS

Table of n, a(n) for n=1..44.

EXAMPLE

1331+sigma(1331)+phi(1331)=4005=T(89).

CROSSREFS

Cf. A069066, A115904, A115905.

Sequence in context: A286164 A211167 A083272 * A192279 A286356 A086422

Adjacent sequences:  A115903 A115904 A115905 * A115907 A115908 A115909

KEYWORD

nonn

AUTHOR

Giovanni Resta, Feb 06 2006

STATUS

approved

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Last modified April 3 21:47 EDT 2020. Contains 333205 sequences. (Running on oeis4.)