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A340299 Numbers k such that (Sum of totatives of k) == 1 (mod Sum of primes dividing k with multiplicity). 2
2, 6, 40, 45, 90, 420, 468, 608, 741, 873, 1216, 1547, 2425, 2451, 2829, 4199, 4208, 6384, 6916, 7552, 7667, 8250, 8325, 8815, 8820, 11008, 11765, 12348, 12408, 12711, 13377, 13920, 14157, 15065, 15246, 15738, 16836, 17640, 17690, 18020, 18791, 19551, 19572, 22161, 22790, 23040, 23856, 24681 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

Robert Israel, Table of n, a(n) for n = 1..2000

FORMULA

k such that A023896(k) == 1 (mod A001414(k)).

EXAMPLE

a(3) = 40 is a term because A023896(40) = 320, A001414(40) = 11, and 320 == 1 (mod 11).

MAPLE

filter:= proc(n) local F, t;

  F:= ifactors(n)[2];

  n*mul((t[1]-1)*t[1]^(t[2]-1), t=F)/2 mod add(t[1]*t[2], t=F) = 1;

end proc:

select(filter, [$2..50000]);

CROSSREFS

Cf. A001414, A023896, A340297.

Sequence in context: A295912 A120492 A028300 * A068207 A331702 A288491

Adjacent sequences:  A340296 A340297 A340298 * A340300 A340301 A340302

KEYWORD

nonn

AUTHOR

J. M. Bergot and Robert Israel, Jan 03 2021

STATUS

approved

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Last modified June 17 00:17 EDT 2021. Contains 345080 sequences. (Running on oeis4.)