id:A055236 - OEIS Search Results

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Sums of two powers of 4.

+0
1

2, 5, 8, 17, 20, 32, 65, 68, 80, 128, 257, 260, 272, 320, 512, 1025, 1028, 1040, 1088, 1280, 2048, 4097, 4100, 4112, 4160, 4352, 5120, 8192, 16385, 16388, 16400, 16448, 16640, 17408, 20480, 32768, 65537, 65540, 65552, 65600, 65792, 66560, 69632 (list; table; graph; listen)

	OFFSET	`0,1`
	FORMULA	`a(n) = 4^(n-trinv(n))+4^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)=4^n+4^k, so as a sequence a(n) = 4^A002262(n)+4^A003056(n).`
	EXAMPLE	`a(4) = 20 = 4^2+4^1`
	CROSSREFS	`Cf. A052216.` `Sequence in context: A048237 A048139 A071085 this_sequence A103041 A006827 A062318` `Adjacent sequences: A055233 A055234 A055235 this_sequence A055237 A055238 A055239`
	KEYWORD	`base,easy,nonn,tabl`
	AUTHOR	`Henry Bottomley (se16(AT)btinternet.com), Jun 22 2000`

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Last modified November 29 12:46 EST 2009. Contains 167659 sequences.

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