id:A055237 - OEIS Search Results

Search: id:A055237

Displaying 1-1 of 1 results found.

page 1

Sums of two powers of 5.

+0
2

2, 6, 10, 26, 30, 50, 126, 130, 150, 250, 626, 630, 650, 750, 1250, 3126, 3130, 3150, 3250, 3750, 6250, 15626, 15630, 15650, 15750, 16250, 18750, 31250, 78126, 78130, 78150, 78250, 78750, 81250, 93750, 156250, 390626, 390630, 390650, 390750 (list; table; graph; listen)

	OFFSET	`0,1`
	FORMULA	`a(n) = 5^(n-trinv(n))+5^trinv(n), where trinv(n) = floor((1+sqrt(1+8*n))/2) = A002262(n) and n-trinv(n) = A003056(n)` `Regarded as a triangle T(n, k)=5^n+5^k, so as a sequence a(n) =5^A002262(n)+5^A003056(n).`
	EXAMPLE	`a(4) = 30 = 5^2+5^1`
	CROSSREFS	`Cf. A052216.` `Sequence in context: A120963 A104142 A079713 this_sequence A057434 A162581 A061547` `Adjacent sequences: A055234 A055235 A055236 this_sequence A055238 A055239 A055240`
	KEYWORD	`base,easy,nonn,tabl`
	AUTHOR	`Henry Bottomley (se16(AT)btinternet.com), Jun 22 2000`

page 1

Search completed in 0.002 seconds

Last modified November 25 20:09 EST 2009. Contains 167514 sequences.

AT&T Labs Research