

A191975


Lowest common multiple of all p1, where prime p divides the nth primary pseudoperfect number A054377(n).


1




OFFSET

1,2


COMMENTS

a(n) is a factor of any exponent k > 0 such that 1^k + 2^k + ... + p^k == 1 (mod p), where p = A054377(n).


REFERENCES

J. Sondow and K. MacMillan, Reducing the ErdosMoser equation 1^n + 2^n + ... + k^n = (k+1)^n modulo k and k^2, Integers 11 (2011), #A34.


LINKS

Table of n, a(n) for n=1..8.
J. Sondow and K. MacMillan, Reducing the ErdosMoser equation 1^n + 2^n + ... + k^n = (k+1)^n modulo k and k^2


FORMULA

a(n) = LCM(p1 : prime p  A054377(n)).


EXAMPLE

A054377(3) = 42 = 2*3*7, so a(3) = LCM(21,31,71) = LCM(1,2,6) = 6.


CROSSREFS

Cf. A054377.
Sequence in context: A127071 A151333 A190626 * A074015 A074021 A050862
Adjacent sequences: A191972 A191973 A191974 * A191976 A191977 A191978


KEYWORD

nonn


AUTHOR

Kieren MacMillan, Jun 20 2011


STATUS

approved



