A340299 Numbers k such that (Sum of totatives of k) == 1 (mod Sum of primes dividing k with multiplicity).

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

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: A120492 A028300 A132192 * 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