A018852 -id:A018852 - cp's OEIS frontend

A138174 a(n) is the smallest cube that begins with n^2.

1, 4096, 9261, 166375, 250047, 3652264, 4913, 64, 8120601, 1000, 12167, 1442897, 16974593, 19683, 225866529, 25672375, 28934443, 3241792, 3616805375, 40001688, 4410944, 4843965888, 529475129, 5764224257, 62570773, 676836152

Offset: 1

Zak Seidov, Mar 05 2008

Differs from A030690.

Cf. A030690, A030691, A018852, A018797, A077729, A077730, A138173.

a(n) = (A138173(n))^3.

Corrected by D. S. McNeil, Dec 12 2010

A260465 a(n) is the smallest number not already in the sequence such that a(n)^3 begins with n.

Original entry on oeis.org

1, 3, 7, 16, 8, 4, 9, 2, 21, 10, 48, 5, 11, 52, 25, 55, 12, 57, 27, 59, 6, 61, 62, 29, 63, 64, 14, 66, 31, 67, 68, 32, 15, 70, 33, 154, 72, 73, 34, 74, 161, 35, 76, 164, 77, 36, 78, 169, 17, 37, 80, 174, 81, 38, 82, 178, 83, 18, 39, 182, 85, 184, 86, 40, 87, 188, 189, 19, 191, 89, 193, 90, 194, 42, 91, 197, 92, 199, 43

Offset: 1

Derek Orr, Jul 26 2015

Conjectured to be a permutation of the natural numbers.

Derek Orr, Table of n, a(n) for n = 1..10000

Cf. A018852.

v=[]; k=1; while(#v<100, d=digits(k^3); D=digits(#v+1); if(#D<=#d, c=1; for(i=1, #D, if(D[i]!=d[i], c=0; break)); if(c&&!vecsearch(vecsort(v), k), v=concat(v, k); k=0)); k++); v

a(n) >= n^(1/3) for all n > 0. If a(n) = n^(1/3), then n is a cube. Note the converse is false: a(27) = 14.

cp's OEIS Frontend

A138174 a(n) is the smallest cube that begins with n^2.

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