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A038481 Sums of 2 distinct powers of 7. 4
8, 50, 56, 344, 350, 392, 2402, 2408, 2450, 2744, 16808, 16814, 16856, 17150, 19208, 117650, 117656, 117698, 117992, 120050, 134456, 823544, 823550, 823592, 823886, 825944, 840350, 941192, 5764802, 5764808, 5764850, 5765144, 5767202 (list; graph; refs; listen; history; text; internal format)
OFFSET
0,1
LINKS
FORMULA
G.f.: ((1-x)*(1-7*x))^(-1) * (2 - 8*x + sum_{k>=0} ((1+5*7^k)*x^(k*(k+1)/2) + (1+41*7^k)*x^(1+k*(k+1)/2))). - Robert Israel, Feb 09 2018
MAPLE
seq(seq(7^i+7^j, j=0..i-1), i=1..10); # Robert Israel, Feb 09 2018
MATHEMATICA
Sort[Total/@Subsets[7^Range[0, 10], {2}]] (* Harvey P. Dale, Jul 29 2015 *)
CROSSREFS
Base 7 interpretation of A038444.
Sequence in context: A299125 A299883 A043398 * A043015 A076286 A299049
KEYWORD
nonn,easy
AUTHOR
STATUS
approved

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Last modified March 28 10:31 EDT 2024. Contains 371240 sequences. (Running on oeis4.)