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A110172 Conjectured n such that phi(n)+phi(k)=phi(n+k) has no solution, where phi is Euler's totient function. 1
3, 15, 21, 39, 45, 57, 69, 105, 147, 165, 177, 195, 213, 273, 285, 315, 345, 393, 399, 465, 489, 525, 585, 615, 633, 645, 651, 681, 717, 777, 807, 813, 843, 855, 879, 885, 903, 915, 933, 939, 1005, 1035, 1041, 1065, 1095, 1149, 1263, 1281, 1293, 1317, 1395 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

All k<10^8 have been checked. All of these numbers are multiples of 3.

LINKS

Table of n, a(n) for n=1..51.

CROSSREFS

Cf. A066426 (least k such that phi(n)+phi(k)=phi(n+k)).

Sequence in context: A243128 A306771 A216521 * A261274 A014493 A147025

Adjacent sequences:  A110169 A110170 A110171 * A110173 A110174 A110175

KEYWORD

nonn

AUTHOR

T. D. Noe, Jul 15 2005

STATUS

approved

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Last modified May 7 20:36 EDT 2021. Contains 343652 sequences. (Running on oeis4.)