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A262715
a(n) = 29^(2*n+1).
4
29, 24389, 20511149, 17249876309, 14507145975869, 12200509765705829, 10260628712958602189, 8629188747598184440949, 7257147736730073114838109, 6103261246589991489578849669, 5132842708382182842735812571629, 4316720717749415770740818372739989
OFFSET
0,1
COMMENTS
29*a(n) is a square.
FORMULA
G.f.: 29/(1 - 841*x).
a(n) = 841*a(n-1).
Sum_{i>=0} (-1)^i/a(i) = 29*A021846; Sum_{i>=0} 1/a(i) = 2.9*A021088. [Bruno Berselli, Oct 06 2015]
MATHEMATICA
29^Range[1, 30, 2]
PROG
(Magma) [29^(2*n+1): n in [0..15]];
(PARI) vector(20, n, n--; 29^(2*n+1)) \\ Altug Alkan, Oct 02 2015
CROSSREFS
Second bisection of A009973 (powers of 29).
Cf. similar sequences of the form p^(2*n+1), with p prime: A004171 (p=2), A013708 (p=3), A013710 (p=5), A013712 (p=7), A013716 (p=11), A013718 (p=13), A013722 (p=17), A013724 (p=19), A013728 (p=23), this sequence (p=29), A262716 (p=31), A262786 (p=37), A262787 (p=41), A155477 (p=43).
Sequence in context: A199369 A127425 A135253 * A274545 A296176 A159437
KEYWORD
nonn,easy
AUTHOR
Vincenzo Librandi, Oct 02 2015
STATUS
approved