A229265 Numbers n such that sigma(n) + tau(n) + phi(n) is a prime, where sigma(n) = A000203(n), tau(n) = A000005(n) and phi(n) = A000010(n).

1, 8, 200, 512, 968, 1458, 3200, 4232, 5618, 5832, 6962, 10368, 16928, 26912, 36992, 40328, 53792, 61952, 84050, 101250, 110450, 140450, 147968, 220448, 247808, 249218, 253472, 257762, 279752, 282752, 320000, 336200, 344450, 359552, 361250, 445568, 472392, 512072

Offset

1,2

Links

Table of n, a(n) for n=1..38.

Example

sigma(200) = 465, tau(200) = 12, phi(200) = 80 and 465 + 12 + 80 = 557 is prime.

Maple

with(numtheory); P:=proc(q) local n; for n from 1 to q do
if isprime(sigma(n)+tau(n)+phi(n)) then print(n); fi; od; end: P(10^6);

Crossrefs

Cf. A000005, A000010, A000203, A009087, A023194, A038344, A055813, A062700, A064205, A115919, A141242, A229264, A229266-A229268.

Sequence in context: A304398 A020329 A232518 * A323562 A034861 A221121

Adjacent sequences: A229262 A229263 A229264 * A229266 A229267 A229268

Keyword

nonn

Author

Paolo P. Lava, Sep 18 2013

Status

approved