OFFSET
1,1
LINKS
Robert Price, Table of n, a(n) for n = 1..10000
FORMULA
a(n) = 1 + A000203(n)^2.
a(n) = 1 + A072861(n). - Omar E. Pol, Jun 19 2015
MAPLE
with(numtheory): A258974:=n->1+sigma(n)^2: seq(A258974(n), n=1..100); # Wesley Ivan Hurt, Jul 09 2015
MATHEMATICA
Table[1 + DivisorSigma[1, n]^2, {n, 10000}]
Table[Cyclotomic[4, DivisorSigma[1, n]], {n, 10000}]
PROG
(Magma) [(1 + DivisorSigma(1, n)^2): n in [1..50]]; // Vincenzo Librandi, Jun 16 2015
(PARI) a(n)=sigma(n)^2+1 \\ Charles R Greathouse IV, Jun 18 2015
CROSSREFS
KEYWORD
easy,nonn
AUTHOR
Robert Price, Jun 15 2015
STATUS
approved