A268868 -id:A268868 - cp's OEIS frontend

A271927 Records in A268868.

1, 2, 4, 6, 9, 23, 25, 71, 73, 263, 265, 911, 913, 5021, 5023, 23291, 23293, 41359, 152681, 152683, 285985, 857951, 857953, 1517571, 1873772, 2498606, 11032457, 11032459, 16576383, 50600183, 50600185, 58908616, 235819403, 235819405, 707458211, 707458213, 1160837269, 3482511803, 3482511805

Offset: 1

N. J. A. Sloane, May 04 2016

nonn

R. J. Mathar, Table of n, a(n) for n = 1..144

Cf. A268868, A271928.

a(n) = A268868(A271928(n)). - R. J. Mathar, May 06 2016

A271928 Positions of records in A268868.

Original entry on oeis.org

1, 3, 4, 5, 6, 7, 8, 9, 10, 12, 13, 15, 16, 29, 30, 44, 45, 50, 56, 57, 72, 73, 74, 84, 93, 95, 108, 109, 113, 116, 117, 123, 126, 127, 128, 129, 144, 145, 146, 157, 158, 159, 160, 161, 162, 165, 166, 179, 191, 215, 223, 271, 272, 275, 276, 286, 287, 289, 290, 296

Offset: 1

N. J. A. Sloane, May 04 2016

nonn

R. J. Mathar, Table of n, a(n) for n = 1..145

Cf. A268868, A271927.

A269004 a(n) is the sum of the prime factors, with repetition, of the sum of all preceding terms, with initial terms a(1)=1 and a(2)=2.

Original entry on oeis.org

1, 2, 3, 5, 11, 13, 12, 47, 49, 24, 167, 169, 503, 505, 1511, 1513, 912, 432, 5879, 5881, 600, 97, 204, 118, 512, 87, 148, 3886, 23291, 23293, 71, 896, 11812, 60, 41359, 2394, 11508, 5529, 8977, 200, 152681, 152683, 604, 16996, 635, 40, 257, 957, 79594, 517, 10155

Offset: 1

David James Sycamore, Feb 17 2016

nonn

Michael De Vlieger, Table of n, a(n) for n = 1..5000 (first 2000 terms from Paolo P. Lava)

Cf. A001414, A268868 (similar sequence with initial terms 1,1).

f[x_] := Total@ Flatten[ConstantArray[#1, #2] & @@@ FactorInteger[x]]; s = 3; {1, 2}~Join~Reap[Do[s += Sow@ f[s], {n, 3, 1000}] ][[-1, 1]] (* Michael De Vlieger, Jun 24 2025 *)

lista(nn) = {va = vector(nn); print1(va[1] = 1, ", "); print1(va[2] = 2, ", "); sp = vecsum(va); for (k=3, nn, f = factor(sp); va[k] = sum(j=1, #f~, f[j, 1]*f[j, 2]); print1(va[k], ", "); sp += va[k]; ); } \\ Michel Marcus, Feb 19 2016

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A271927 Records in A268868.

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A271928 Positions of records in A268868.

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A269004 a(n) is the sum of the prime factors, with repetition, of the sum of all preceding terms, with initial terms a(1)=1 and a(2)=2.

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