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A172521 Partial sums of A078902. 0
17, 114, 371, 708, 1589, 5286, 15943, 32504, 81801, 147338, 214315, 303356, 452413, 1300014, 2288431, 3434528, 5406625, 7476866, 9999123, 12836084, 16389861, 20349158, 24747735, 30133496, 37300393, 48373610, 66027291, 98557468 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

It is unknown if this is a finite or infinite sequence. Can it ever have a prime value after a(1) = 17? It can be semiprime, as 371 = 7 * 53; 1589 = 7 * 227; 15943 = 107 * 149; 214315 = 5 * 42863; 2288431 = 23 * 99497; and 16389861 = 3 * 5463287.

LINKS

Table of n, a(n) for n=1..28.

Eric W. Weisstein, Generalized Fermat Number.

FORMULA

SUM[i=1..n] {primes of the form (k+1)^2^m + k^2^m, with m>1.}

EXAMPLE

a(29) = 17 + 97 + 257 + 337 + 881 + 3697 + 10657 + 16561 + 49297 + 65537 + 66977 + 89041 + 149057 + 847601 + 988417 + 1146097 + 1972097 + 2070241 + 2522257 + 2836961 + 3553777 + 3959297 + 4398577 + 5385761 + 7166897 + 11073217 + 17653681 + 32530177 + 41532497 + 44048497.

CROSSREFS

Cf. A000040, A001358, A019434, A077659, A078900, A078901, A078902, A080131, A080208.

Sequence in context: A299223 A197360 A289472 * A226688 A070144 A070209

Adjacent sequences:  A172518 A172519 A172520 * A172522 A172523 A172524

KEYWORD

nonn

AUTHOR

Jonathan Vos Post, Feb 06 2010

STATUS

approved

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Last modified August 13 02:09 EDT 2020. Contains 336441 sequences. (Running on oeis4.)