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This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

A172460 Partial sums of economical numbers A046759.

Original entry on oeis.org

125, 253, 496, 752, 1095, 1607, 2232, 2961, 3985, 5014, 6229, 7479, 8759, 10090, 11459, 12917, 14453, 16134, 17835, 19550, 21342, 23191, 25066, 27114, 29301, 31498, 33707, 36108, 38668, 41477, 44602, 48083, 51667, 55312, 59033, 63129
Offset: 1

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Author

Jonathan Vos Post, Feb 03 2010

Keywords

Comments

The subsequence of prime partial sum of economical numbers begins: 1607, 6229, 12917, 76367. The subsequence of economical partial sum of economical numbers begins: 125; what is the first nontrivial economical partial sum of economical numbers?

Examples

			a(41) = 125 + 128 + 243 + 256 + 343 + 512 + 625 + 729 + 1024 + 1029 + 1215 + 1250 + 1280 + 1331 + 1369 + 1458 + 1536 + 1681 + 1701 + 1715 + 1792 + 1849 + 1875 + 2048 + 2187 + 2197 + 2209 + 2401 + 2560 + 2809 + 3125 + 3481 + 3584 + 3645 + 3721 + 4096 + 4374 + 4375 + 4489 + 4802 + 4913.

Crossrefs

Cf. A000961, A046758, A046759, A046760.

Formula

a(n) = SUM[i=1..n] {n written as a product of primes raised to powers, where D(n) = number of digits in product, l(n) = number of digits in n; sequence gives n such that D(n)

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