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A349660
Numbers which are the sum of a prime and the square of the next prime.
4
11, 28, 54, 128, 180, 302, 378, 548, 864, 990, 1400, 1718, 1890, 2252, 2856, 3534, 3780, 4550, 5108, 5400, 6314, 6968, 8004, 9498, 10298, 10710, 11552, 11988, 12878, 16242, 17288, 18900, 19458, 22340, 22950, 24800, 26726, 28052, 30096, 32214, 32940, 36662
OFFSET
1,1
LINKS
FORMULA
a(n) = prime(n) + prime(n+1)^2.
a(n) = A000040(n) + A001248(n+1).
a(n) = A036690(n+1) - A001223(n).
a(n) = A001043(n) + A036689(n+1). - Michel Marcus, Nov 24 2021
EXAMPLE
a(2) = 3 + 5^2 = 28; a(3) = 5 + 7^2 = 54.
MATHEMATICA
nterms=100; Table[Prime[n]+Prime[n+1]^2, {n, nterms}] (* Paolo Xausa, Nov 24 2021 *)
PROG
(Python) from sympy import sieve;
for n in range(1, 10001): print(sieve[n] + sieve[n+1]**2)
(PARI) a(n) = prime(n) + prime(n+1)^2; \\ Michel Marcus, Nov 24 2021
KEYWORD
nonn,easy
AUTHOR
Karl-Heinz Hofmann, Nov 24 2021
STATUS
approved