

A226962


Numbers n such that 1^n + 2^n + 3^n + ... + n^n == 4 (mod n).


10




OFFSET

1,2


COMMENTS

Also, numbers n such that B(n)*n == 4 (mod n), where B(n) is the nth Bernoulli number. Equivalently, SUM[prime p, (p1) divides n] n/p == 4 (mod n). There are no other terms below 10^15.  Max Alekseyev, Aug 26 2013


LINKS



MATHEMATICA

Select[Range[10000], Mod[Sum[PowerMod[i, #, #], {i, #}], #] == 4 &]


PROG



CROSSREFS

Solutions to 1^n+2^n+...+n^n == m (mod n): A005408 (m=0), A014117 (m=1), A226960 (m=2), A226961 (m=3), this sequence (m=4), A226963 (m=5), A226964 (m=6), A226965 (m=7), A226966 (m=8), A226967 (m=9), A280041 (m=19), A280043 (m=43), A302343 (m=79), A302344 (m=193).


KEYWORD

nonn,more


AUTHOR



EXTENSIONS



STATUS

approved



