278 Jean-Marie De Koninck
1 334 961
the number of possible arrangements of the integers 1,2,. . . ,10 with the restric-
tion that the integer j must not be in the j-th position for each j, 1 j 10
(see the number 265).
1 362 239
the sixth solution of σ2(n) = σ2(n + 2) (see the number 1 079).
1 373 653
the smallest strong pseudoprime with respect to bases 2 and 3.
1 398 269
the exponent of the
35th
Mersenne prime
21 398 269
1 (Armengaud, 1996):
G.F. Woltman wrote a programme based on the Lucas-Lehmer test and made
it accessible on the WEB (see www.mersenne.org) for anyone who wants to find
the largest Mersenne prime; the 36th (22 976 220 1), 37th (23 021 377 1), 38th
(26 972 593 1), 39th (213 477 966 1), 40th (220,996 011 1), 41rst (224 036 583 1),
42nd (225 964 951−1), 43rd (230 402 457−1), 44th (232 582 657−1), 45th (237 156 667−1)
and 46th (243 112 609 1) Mersenne primes have been found by volunteers using
Woltman’s programme.
1 413 721
the fifth number which is both a triangular number and a perfect square:
1 413 721 =
1681(1681+1)
2
=
11892
(see the number 36).
1 416 329
the smallest prime number q such that

p≤q
p is divisible by 510 510 (= 2 · 3 ·
5 · 7 · 11 · 13 · 17): here this sum is equal to 73 454 220 840 (see the number 269).
1 419 263
the largest known prime number p such that P
(p2
−1) 19 and P
(p2
−1) = 19:
here 1 419 2632 1 = 212 · 32 · 7 · 11 · 133 · 17 · 19 (see the number 4 801).
1 441 440
the 12th colossally abundant number (see the number 55 440).
Previous Page Next Page