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A132315 Sum of the non-fourth powers less than or equal to n. 1
0, 2, 5, 9, 14, 20, 27, 35, 44, 54, 65, 77, 90, 104, 119, 119, 136, 154, 173, 193, 214, 236, 259, 283, 308, 334, 361, 389, 418, 448, 479, 511, 544, 578, 613, 649, 686, 724, 763, 803, 844, 886, 929, 973, 1018, 1064, 1111, 1159, 1208, 1258, 1309, 1361, 1414, 1468 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

LINKS

Table of n, a(n) for n=1..54.

FORMULA

Let r = floor(n^(1/4)). Then a(n) = n(n+1)/2 - (r^5/5+r^4/2+r^3/3-r/30).

EXAMPLE

Let n=16.

The sum of the non-quartic numbers <= 16 is 2+3+4+5+6+7+8+9+10+11+12+13+14+15 = 119, the 16th entry in the sequence.

PROG

(PARI) g4(n)=for(x=1, n, r=floor(x^(1/4)); sum4=r^5/5+r^4/2+r^3/3-r/30; sn=x*(x+1)/2; print1(sn-sum4", "))

CROSSREFS

Sequence in context: A132296 A275586 A075543 * A079509 A132336 A272370

Adjacent sequences:  A132312 A132313 A132314 * A132316 A132317 A132318

KEYWORD

nonn

AUTHOR

Cino Hilliard, Nov 07 2007

STATUS

approved

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Last modified March 23 21:31 EDT 2017. Contains 283985 sequences.